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<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"><html xmlns="http://www.w3.org/1999/xhtml"><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /><title>Nix Package Manager Guide</title><meta name="generator" content="DocBook XSL Stylesheets V1.79.2" /></head><body><div class="book"><div class="titlepage"><div><div><h1 class="title"><a id="idm139733328760992"></a>Nix Package Manager Guide</h1></div><div><h2 class="subtitle">Version 3.0</h2></div><div><div class="author"><h3 class="author"><span class="firstname">Eelco</span> <span class="surname">Dolstra</span></h3></div></div><div><p class="copyright">Copyright © 2004-2018 Eelco Dolstra</p></div></div><hr /></div><div class="toc"><dl class="toc"><dt><span class="part"><a href="#chap-introduction">I. Introduction</a></span></dt><dd><dl><dt><span class="chapter"><a href="#ch-about-nix">1. About Nix</a></span></dt><dt><span class="chapter"><a href="#chap-quick-start">2. Quick Start</a></span></dt></dl></dd><dt><span class="part"><a href="#chap-installation">II. Installation</a></span></dt><dd><dl><dt><span class="chapter"><a href="#ch-supported-platforms">3. Supported Platforms</a></span></dt><dt><span class="chapter"><a href="#ch-installing-binary">4. Installing a Binary Distribution</a></span></dt><dd><dl><dt><span class="section"><a href="#sect-single-user-installation">4.1. Single User Installation</a></span></dt><dt><span class="section"><a href="#sect-multi-user-installation">4.2. Multi User Installation</a></span></dt><dt><span class="section"><a href="#sect-macos-installation">4.3. macOS Installation</a></span></dt><dd><dl><dt><span class="section"><a href="#sect-macos-installation-change-store-prefix">4.3.1. Change the Nix store path prefix</a></span></dt><dt><span class="section"><a href="#sect-macos-installation-encrypted-volume">4.3.2. Use a separate encrypted volume</a></span></dt><dt><span class="section"><a href="#sect-macos-installation-symlink">4.3.3. Symlink the Nix store to a custom location</a></span></dt><dt><span class="section"><a href="#sect-macos-installation-recommended-notes">4.3.4. Notes on the recommended approach</a></span></dt></dl></dd><dt><span class="section"><a href="#sect-nix-install-pinned-version-url">4.4. Installing a pinned Nix version from a URL</a></span></dt><dt><span class="section"><a href="#sect-nix-install-binary-tarball">4.5. Installing from a binary tarball</a></span></dt></dl></dd><dt><span class="chapter"><a href="#ch-installing-source">5. Installing Nix from Source</a></span></dt><dd><dl><dt><span class="section"><a href="#sec-prerequisites-source">5.1. Prerequisites</a></span></dt><dt><span class="section"><a href="#sec-obtaining-source">5.2. Obtaining a Source Distribution</a></span></dt><dt><span class="section"><a href="#sec-building-source">5.3. Building Nix from Source</a></span></dt></dl></dd><dt><span class="chapter"><a href="#ch-nix-security">6. Security</a></span></dt><dd><dl><dt><span class="section"><a href="#sec-single-user">6.1. Single-User Mode</a></span></dt><dt><span class="section"><a href="#ssec-multi-user">6.2. Multi-User Mode</a></span></dt></dl></dd><dt><span class="chapter"><a href="#ch-env-variables">7. Environment Variables</a></span></dt><dd><dl><dt><span class="section"><a href="#sec-nix-ssl-cert-file">7.1. <code class="envar">NIX_SSL_CERT_FILE</code></a></span></dt><dd><dl><dt><span class="section"><a href="#sec-nix-ssl-cert-file-with-nix-daemon-and-macos">7.1.1. <code class="envar">NIX_SSL_CERT_FILE</code> with macOS and the Nix daemon</a></span></dt><dt><span class="section"><a href="#sec-installer-proxy-settings">7.1.2. Proxy Environment Variables</a></span></dt></dl></dd></dl></dd></dl></dd><dt><span class="chapter"><a href="#ch-upgrading-nix">8. Upgrading Nix</a></span></dt><dt><span class="part"><a href="#chap-package-management">III. Package Management</a></span></dt><dd><dl><dt><span class="chapter"><a href="#ch-basic-package-mgmt">9. Basic Package Management</a></span></dt><dt><span class="ch
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Spot-Checking Build Determinism
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</a></span></dt><dt><span class="section"><a href="#idm139733300495744">18.2.
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Automatic and Optionally Enforced Determinism Verification
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</a></span></dt></dl></dd><dt><span class="chapter"><a href="#chap-post-build-hook">19. Using the <code class="option"><a class="option" href="#conf-post-build-hook">post-build-hook</a></code></a></span></dt><dd><dl><dt><span class="section"><a href="#chap-post-build-hook-caveats">19.1. Implementation Caveats</a></span></dt><dt><span class="section"><a href="#idm139733300481840">19.2. Prerequisites</a></span></dt><dt><span class="section"><a href="#idm139733300479440">19.3. Set up a Signing Key</a></span></dt><dt><span class="section"><a href="#idm139733300473952">19.4. Implementing the build hook</a></span></dt><dt><span class="section"><a href="#idm139733300467040">19.5. Updating Nix Configuration</a></span></dt><dt><span class="section"><a href="#idm139733300464016">19.6. Testing</a></span></dt><dt><span class="section"><a href="#idm139733300459088">19.7. Conclusion</a></span></dt></dl></dd></dl></dd><dt><span class="part"><a href="#part-command-ref">VI. Command Reference</a></span></dt><dd><dl><dt><span class="chapter"><a href="#sec-common-options">20. Common Options</a></span></dt><dt><span class="chapter"><a href="#sec-common-env">21. Common Environment Variables</a></span></dt><dt><span class="chapter"><a href="#ch-main-commands">22. Main Commands</a></span></dt><dd><dl><dt><span class="refentrytitle"><a href="#sec-nix-env">nix-env</a></span><span class="refpurpose"> — manipulate or query Nix user environments</span></dt><dt><span class="refentrytitle"><a href="#sec-nix-build">nix-build</a></span><span class="refpurpose"> — build a Nix expression</span></dt><dt><span class="refentrytitle"><a href="#sec-nix-shell">nix-shell</a></span><span class="refpurpose"> — start an interactive shell based on a Nix expression</span></dt><dt><span class="refentrytitle"><a href="#sec-nix-store">nix-store</a></span><span class="refpurpose"> — manipulate or query the Nix store</span></dt></dl></dd><dt><span class="chapter"><a href="#ch-utilities">23. Utilities</a></span></dt><dd><dl><dt><span class="refentrytitle"><a href="#sec-nix-channel">nix-channel</a></span><span class="refpurpose"> — manage Nix channels</span></dt><dt><span class="refentrytitle"><a href="#sec-nix-collect-garbage">nix-collect-garbage</a></span><span class="refpurpose"> — delete unreachable store paths</span></dt><dt><span class="refentrytitle"><a href="#sec-nix-copy-closure">nix-copy-closure</a></span><span class="refpurpose"> — copy a closure to or from a remote machine via SSH</span></dt><dt><span class="refentrytitle"><a href="#sec-nix-daemon">nix-daemon</a></span><span class="refpurpose"> — Nix multi-user support daemon</span></dt><dt><span class="refentrytitle"><a href="#sec-nix-hash">nix-hash</a></span><span class="refpurpose"> — compute the cryptographic hash of a path</span></dt><dt><span class="refentrytitle"><a href="#sec-nix-instantiate">nix-instantiate</a></span><span class="refpurpose"> — instantiate store derivations from Nix expressions</span></dt><dt><span class="refentrytitle"><a href="#sec-nix-prefetch-url">nix-prefetch-url</a></span><span class="refpurpose"> — copy a file from a URL into the store and print its hash</span></dt></dl></dd><dt><span class="chapter"><a href="#ch-files">24. Files</a></span></dt><dd><dl><dt><span class="refentrytitle"><a href="#sec-conf-file">nix.conf</a></span><span class="refpurpose"> — Nix configuration file</span></dt></dl></dd></dl></dd><dt><span class="appendix"><a href="#part-glossary">A. Glossary</a></span></dt><dt><span class="appendix"><a href="#chap-hacking">B. Hacking</a></span></dt><dt><span class="appendix"><a href="#sec-relnotes">C. Nix Release Notes</a></span></dt><dd><dl><dt><span class="section"><a href="#ssec-relnotes-2.3">C.1. Release 2.3 (2019-09-04)</a></span></dt><dt><span class="section"><a href="#ssec-relnotes-2.2">C.2. Release 2.2 (2019-01-11)</a></span></dt><dt><span class="section"><a href="#ssec-relnotes-2.1">C.3. Release 2.1 (2018-09-02)</a></span></dt><dt><span class="section"><a href="#ssec-relnotes-2.0">C.4. Release 2.0 (2018-02-22)</a></span></dt><dt><sp
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This means that it treats packages like values in purely functional
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programming languages such as Haskell — they are built by functions
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that don’t have side-effects, and they never change after they have
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been built. Nix stores packages in the <span class="emphasis"><em>Nix
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store</em></span>, usually the directory
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<code class="filename">/nix/store</code>, where each package has its own unique
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subdirectory such as
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</p><pre class="programlisting">
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/nix/store/b6gvzjyb2pg0kjfwrjmg1vfhh54ad73z-firefox-33.1/
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</pre><p>
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where <code class="literal">b6gvzjyb2pg0…</code> is a unique identifier for the
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package that captures all its dependencies (it’s a cryptographic hash
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of the package’s build dependency graph). This enables many powerful
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features.</p><div class="simplesect"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a id="idm139733302010000"></a>Multiple versions</h2></div></div></div><p>You can have multiple versions or variants of a package
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installed at the same time. This is especially important when
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different applications have dependencies on different versions of the
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same package — it prevents the “DLL hell”. Because of the hashing
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scheme, different versions of a package end up in different paths in
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the Nix store, so they don’t interfere with each other.</p><p>An important consequence is that operations like upgrading or
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uninstalling an application cannot break other applications, since
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these operations never “destructively” update or delete files that are
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used by other packages.</p></div><div class="simplesect"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a id="idm139733302007296"></a>Complete dependencies</h2></div></div></div><p>Nix helps you make sure that package dependency specifications
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are complete. In general, when you’re making a package for a package
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management system like RPM, you have to specify for each package what
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its dependencies are, but there are no guarantees that this
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specification is complete. If you forget a dependency, then the
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package will build and work correctly on <span class="emphasis"><em>your</em></span>
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machine if you have the dependency installed, but not on the end
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user's machine if it's not there.</p><p>Since Nix on the other hand doesn’t install packages in “global”
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locations like <code class="filename">/usr/bin</code> but in package-specific
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directories, the risk of incomplete dependencies is greatly reduced.
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This is because tools such as compilers don’t search in per-packages
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directories such as
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<code class="filename">/nix/store/5lbfaxb722zp…-openssl-0.9.8d/include</code>,
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so if a package builds correctly on your system, this is because you
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specified the dependency explicitly. This takes care of the build-time
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dependencies.</p><p>Once a package is built, runtime dependencies are found by
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scanning binaries for the hash parts of Nix store paths (such as
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<code class="literal">r8vvq9kq…</code>). This sounds risky, but it works
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extremely well.</p></div><div class="simplesect"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a id="idm139733302002080"></a>Multi-user support</h2></div></div></div><p>Nix has multi-user support. This means that non-privileged
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users can securely install software. Each user can have a different
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<span class="emphasis"><em>profile</em></span>, a set of packages in the Nix store that
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appear in the user’s <code class="envar">PATH</code>. If a user installs a
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package that another user has already installed previously, the
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package won’t be built or downloaded a second time. At the same time,
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it is not possible for one user to inject a Trojan horse into a
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package that might be used by another user.</p></div><div class="simplesect"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a id="idm139733301999344"></a>Atomic upgrades and rollbacks</h2></div></div></div><p>Since package management operations never overwrite packages in
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the Nix store but just add new versions in different paths, they are
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<span class="emphasis"><em>atomic</em></span>. So during a package upgrade, there is no
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time window in which the package has some files from the old version
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and some files from the new version — which would be bad because a
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program might well crash if it’s started during that period.</p><p>And since packages aren’t overwritten, the old versions are still
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there after an upgrade. This means that you can <span class="emphasis"><em>roll
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back</em></span> to the old version:</p><pre class="screen">
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$ nix-env --upgrade <em class="replaceable"><code>some-packages</code></em>
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$ nix-env --rollback
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</pre></div><div class="simplesect"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a id="idm139733301995248"></a>Garbage collection</h2></div></div></div><p>When you uninstall a package like this…
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</p><pre class="screen">
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$ nix-env --uninstall firefox
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</pre><p>
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the package isn’t deleted from the system right away (after all, you
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might want to do a rollback, or it might be in the profiles of other
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users). Instead, unused packages can be deleted safely by running the
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<span class="emphasis"><em>garbage collector</em></span>:
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</p><pre class="screen">
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$ nix-collect-garbage
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</pre><p>
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This deletes all packages that aren’t in use by any user profile or by
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a currently running program.</p></div><div class="simplesect"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a id="idm139733301992112"></a>Functional package language</h2></div></div></div><p>Packages are built from <span class="emphasis"><em>Nix expressions</em></span>,
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which is a simple functional language. A Nix expression describes
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everything that goes into a package build action (a “derivation”):
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other packages, sources, the build script, environment variables for
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the build script, etc. Nix tries very hard to ensure that Nix
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expressions are <span class="emphasis"><em>deterministic</em></span>: building a Nix
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expression twice should yield the same result.</p><p>Because it’s a functional language, it’s easy to support
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building variants of a package: turn the Nix expression into a
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function and call it any number of times with the appropriate
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arguments. Due to the hashing scheme, variants don’t conflict with
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each other in the Nix store.</p></div><div class="simplesect"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a id="idm139733301988512"></a>Transparent source/binary deployment</h2></div></div></div><p>Nix expressions generally describe how to build a package from
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source, so an installation action like
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</p><pre class="screen">
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$ nix-env --install firefox
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</pre><p>
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<span class="emphasis"><em>could</em></span> cause quite a bit of build activity, as not
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only Firefox but also all its dependencies (all the way up to the C
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library and the compiler) would have to built, at least if they are
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not already in the Nix store. This is a <span class="emphasis"><em>source deployment
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model</em></span>. For most users, building from source is not very
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pleasant as it takes far too long. However, Nix can automatically
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skip building from source and instead use a <span class="emphasis"><em>binary
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cache</em></span>, a web server that provides pre-built binaries. For
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instance, when asked to build
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<code class="literal">/nix/store/b6gvzjyb2pg0…-firefox-33.1</code> from source,
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Nix would first check if the file
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<code class="uri">https://cache.nixos.org/b6gvzjyb2pg0….narinfo</code> exists, and
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if so, fetch the pre-built binary referenced from there; otherwise, it
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would fall back to building from source.</p></div><div class="simplesect"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a id="idm139733301983504"></a>Nix Packages collection</h2></div></div></div><p>We provide a large set of Nix expressions containing hundreds of
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existing Unix packages, the <span class="emphasis"><em>Nix Packages
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collection</em></span> (Nixpkgs).</p></div><div class="simplesect"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a id="idm139733301981888"></a>Managing build environments</h2></div></div></div><p>Nix is extremely useful for developers as it makes it easy to
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automatically set up the build environment for a package. Given a
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Nix expression that describes the dependencies of your package, the
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command <span class="command"><strong>nix-shell</strong></span> will build or download those
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dependencies if they’re not already in your Nix store, and then start
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a Bash shell in which all necessary environment variables (such as
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compiler search paths) are set.</p><p>For example, the following command gets all dependencies of the
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Pan newsreader, as described by <a class="link" href="https://github.com/NixOS/nixpkgs/blob/master/pkgs/applications/networking/newsreaders/pan/default.nix" target="_top">its
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Nix expression</a>:</p><pre class="screen">
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$ nix-shell '<nixpkgs>' -A pan
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</pre><p>You’re then dropped into a shell where you can edit, build and test
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the package:</p><pre class="screen">
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[nix-shell]$ tar xf $src
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[nix-shell]$ cd pan-*
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[nix-shell]$ ./configure
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[nix-shell]$ make
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[nix-shell]$ ./pan/gui/pan
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</pre></div><div class="simplesect"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a id="idm139733301976352"></a>Portability</h2></div></div></div><p>Nix runs on Linux and macOS.</p></div><div class="simplesect"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a id="idm139733301975296"></a>NixOS</h2></div></div></div><p>NixOS is a Linux distribution based on Nix. It uses Nix not
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just for package management but also to manage the system
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configuration (e.g., to build configuration files in
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<code class="filename">/etc</code>). This means, among other things, that it
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is easy to roll back the entire configuration of the system to an
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earlier state. Also, users can install software without root
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privileges. For more information and downloads, see the <a class="link" href="http://nixos.org/" target="_top">NixOS homepage</a>.</p></div><div class="simplesect"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a id="idm139733301972848"></a>License</h2></div></div></div><p>Nix is released under the terms of the <a class="link" href="http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html" target="_top">GNU
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LGPLv2.1 or (at your option) any later version</a>.</p></div></div><div class="chapter"><div class="titlepage"><div><div><h2 class="title"><a id="chap-quick-start"></a>Chapter 2. Quick Start</h2></div></div></div><p>This chapter is for impatient people who don't like reading
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documentation. For more in-depth information you are kindly referred
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to subsequent chapters.</p><div class="procedure"><ol class="procedure" type="1"><li class="step"><p>Install single-user Nix by running the following:
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</p><pre class="screen">
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$ bash <(curl -L https://nixos.org/nix/install)
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</pre><p>
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This will install Nix in <code class="filename">/nix</code>. The install script
|
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will create <code class="filename">/nix</code> using <span class="command"><strong>sudo</strong></span>,
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so make sure you have sufficient rights. (For other installation
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methods, see <a class="xref" href="#chap-installation" title="Part II. Installation">Part II, “Installation”</a>.)</p></li><li class="step"><p>See what installable packages are currently available
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in the channel:
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</p><pre class="screen">
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$ nix-env -qa
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docbook-xml-4.3
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docbook-xml-4.5
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firefox-33.0.2
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hello-2.9
|
|||
|
|
libxslt-1.1.28
|
|||
|
|
<em class="replaceable"><code>...</code></em></pre><p>
|
|||
|
|
|
|||
|
|
</p></li><li class="step"><p>Install some packages from the channel:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-env -i hello</pre><p>
|
|||
|
|
|
|||
|
|
This should download pre-built packages; it should not build them
|
|||
|
|
locally (if it does, something went wrong).</p></li><li class="step"><p>Test that they work:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ which hello
|
|||
|
|
/home/eelco/.nix-profile/bin/hello
|
|||
|
|
$ hello
|
|||
|
|
Hello, world!
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
</p></li><li class="step"><p>Uninstall a package:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-env -e hello</pre><p>
|
|||
|
|
|
|||
|
|
</p></li><li class="step"><p>You can also test a package without installing it:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-shell -p hello
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
This builds or downloads GNU Hello and its dependencies, then drops
|
|||
|
|
you into a Bash shell where the <span class="command"><strong>hello</strong></span> command is
|
|||
|
|
present, all without affecting your normal environment:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
[nix-shell:~]$ hello
|
|||
|
|
Hello, world!
|
|||
|
|
|
|||
|
|
[nix-shell:~]$ exit
|
|||
|
|
|
|||
|
|
$ hello
|
|||
|
|
hello: command not found
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
</p></li><li class="step"><p>To keep up-to-date with the channel, do:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-channel --update nixpkgs
|
|||
|
|
$ nix-env -u '*'</pre><p>
|
|||
|
|
|
|||
|
|
The latter command will upgrade each installed package for which there
|
|||
|
|
is a “newer” version (as determined by comparing the version
|
|||
|
|
numbers).</p></li><li class="step"><p>If you're unhappy with the result of a
|
|||
|
|
<span class="command"><strong>nix-env</strong></span> action (e.g., an upgraded package turned
|
|||
|
|
out not to work properly), you can go back:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-env --rollback</pre><p>
|
|||
|
|
|
|||
|
|
</p></li><li class="step"><p>You should periodically run the Nix garbage collector
|
|||
|
|
to get rid of unused packages, since uninstalls or upgrades don't
|
|||
|
|
actually delete them:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-collect-garbage -d</pre><p>
|
|||
|
|
|
|||
|
|
|
|||
|
|
|
|||
|
|
</p></li></ol></div></div></div><div class="part"><div class="titlepage"><div><div><h1 class="title"><a id="chap-installation"></a>Part II. Installation</h1></div></div></div><div class="partintro"><div></div><p>This section describes how to install and configure Nix for first-time use.</p></div><div class="chapter"><div class="titlepage"><div><div><h2 class="title"><a id="ch-supported-platforms"></a>Chapter 3. Supported Platforms</h2></div></div></div><p>Nix is currently supported on the following platforms:
|
|||
|
|
|
|||
|
|
</p><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><p>Linux (i686, x86_64, aarch64).</p></li><li class="listitem"><p>macOS (x86_64).</p></li></ul></div><p>
|
|||
|
|
|
|||
|
|
</p></div><div class="chapter"><div class="titlepage"><div><div><h2 class="title"><a id="ch-installing-binary"></a>Chapter 4. Installing a Binary Distribution</h2></div></div></div><p>
|
|||
|
|
If you are using Linux or macOS versions up to 10.14 (Mojave), the
|
|||
|
|
easiest way to install Nix is to run the following command:
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ sh <(curl -L https://nixos.org/nix/install)
|
|||
|
|
</pre><p>
|
|||
|
|
If you're using macOS 10.15 (Catalina) or newer, consult
|
|||
|
|
<a class="link" href="#sect-macos-installation" title="4.3. macOS Installation">the macOS installation instructions</a>
|
|||
|
|
before installing.
|
|||
|
|
</p><p>
|
|||
|
|
As of Nix 2.1.0, the Nix installer will always default to creating a
|
|||
|
|
single-user installation, however opting in to the multi-user
|
|||
|
|
installation is highly recommended.
|
|||
|
|
|
|||
|
|
</p><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a id="sect-single-user-installation"></a>4.1. Single User Installation</h2></div></div></div><p>
|
|||
|
|
To explicitly select a single-user installation on your system:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
sh <(curl -L https://nixos.org/nix/install) --no-daemon
|
|||
|
|
</pre><p>
|
|||
|
|
</p><p>
|
|||
|
|
This will perform a single-user installation of Nix, meaning that
|
|||
|
|
<code class="filename">/nix</code> is owned by the invoking user. You should
|
|||
|
|
run this under your usual user account, <span class="emphasis"><em>not</em></span> as
|
|||
|
|
root. The script will invoke <span class="command"><strong>sudo</strong></span> to create
|
|||
|
|
<code class="filename">/nix</code> if it doesn’t already exist. If you don’t
|
|||
|
|
have <span class="command"><strong>sudo</strong></span>, you should manually create
|
|||
|
|
<code class="filename">/nix</code> first as root, e.g.:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ mkdir /nix
|
|||
|
|
$ chown alice /nix
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
The install script will modify the first writable file from amongst
|
|||
|
|
<code class="filename">.bash_profile</code>, <code class="filename">.bash_login</code>
|
|||
|
|
and <code class="filename">.profile</code> to source
|
|||
|
|
<code class="filename">~/.nix-profile/etc/profile.d/nix.sh</code>. You can set
|
|||
|
|
the <code class="envar">NIX_INSTALLER_NO_MODIFY_PROFILE</code> environment
|
|||
|
|
variable before executing the install script to disable this
|
|||
|
|
behaviour.
|
|||
|
|
</p><p>You can uninstall Nix simply by running:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ rm -rf /nix
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
</p></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a id="sect-multi-user-installation"></a>4.2. Multi User Installation</h2></div></div></div><p>
|
|||
|
|
The multi-user Nix installation creates system users, and a system
|
|||
|
|
service for the Nix daemon.
|
|||
|
|
</p><div class="itemizedlist"><p class="title"><strong>Supported Systems</strong></p><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><p>Linux running systemd, with SELinux disabled</p></li><li class="listitem"><p>macOS</p></li></ul></div><p>
|
|||
|
|
You can instruct the installer to perform a multi-user
|
|||
|
|
installation on your system:
|
|||
|
|
</p><pre class="screen">sh <(curl -L https://nixos.org/nix/install) --daemon</pre><p>
|
|||
|
|
The multi-user installation of Nix will create build users between
|
|||
|
|
the user IDs 30001 and 30032, and a group with the group ID 30000.
|
|||
|
|
|
|||
|
|
You should run this under your usual user account,
|
|||
|
|
<span class="emphasis"><em>not</em></span> as root. The script will invoke
|
|||
|
|
<span class="command"><strong>sudo</strong></span> as needed.
|
|||
|
|
</p><div class="note"><h3 class="title">Note</h3><p>
|
|||
|
|
If you need Nix to use a different group ID or user ID set, you
|
|||
|
|
will have to download the tarball manually and <a class="link" href="#sect-nix-install-binary-tarball" title="4.5. Installing from a binary tarball">edit the install
|
|||
|
|
script</a>.
|
|||
|
|
</p></div><p>
|
|||
|
|
The installer will modify <code class="filename">/etc/bashrc</code>, and
|
|||
|
|
<code class="filename">/etc/zshrc</code> if they exist. The installer will
|
|||
|
|
first back up these files with a
|
|||
|
|
<code class="literal">.backup-before-nix</code> extension. The installer
|
|||
|
|
will also create <code class="filename">/etc/profile.d/nix.sh</code>.
|
|||
|
|
</p><p>You can uninstall Nix with the following commands:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
sudo rm -rf /etc/profile/nix.sh /etc/nix /nix ~root/.nix-profile ~root/.nix-defexpr ~root/.nix-channels ~/.nix-profile ~/.nix-defexpr ~/.nix-channels
|
|||
|
|
|
|||
|
|
# If you are on Linux with systemd, you will need to run:
|
|||
|
|
sudo systemctl stop nix-daemon.socket
|
|||
|
|
sudo systemctl stop nix-daemon.service
|
|||
|
|
sudo systemctl disable nix-daemon.socket
|
|||
|
|
sudo systemctl disable nix-daemon.service
|
|||
|
|
sudo systemctl daemon-reload
|
|||
|
|
|
|||
|
|
# If you are on macOS, you will need to run:
|
|||
|
|
sudo launchctl unload /Library/LaunchDaemons/org.nixos.nix-daemon.plist
|
|||
|
|
sudo rm /Library/LaunchDaemons/org.nixos.nix-daemon.plist
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
There may also be references to Nix in
|
|||
|
|
<code class="filename">/etc/profile</code>,
|
|||
|
|
<code class="filename">/etc/bashrc</code>, and
|
|||
|
|
<code class="filename">/etc/zshrc</code> which you may remove.
|
|||
|
|
</p></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a id="sect-macos-installation"></a>4.3. macOS Installation</h2></div></div></div><p>
|
|||
|
|
Starting with macOS 10.15 (Catalina), the root filesystem is read-only.
|
|||
|
|
This means <code class="filename">/nix</code> can no longer live on your system
|
|||
|
|
volume, and that you'll need a workaround to install Nix.
|
|||
|
|
</p><p>
|
|||
|
|
The recommended approach, which creates an unencrypted APFS volume
|
|||
|
|
for your Nix store and a "synthetic" empty directory to mount it
|
|||
|
|
over at <code class="filename">/nix</code>, is least likely to impair Nix
|
|||
|
|
or your system.
|
|||
|
|
</p><div class="note"><h3 class="title">Note</h3><p>
|
|||
|
|
With all separate-volume approaches, it's possible something on
|
|||
|
|
your system (particularly daemons/services and restored apps) may
|
|||
|
|
need access to your Nix store before the volume is mounted. Adding
|
|||
|
|
additional encryption makes this more likely.
|
|||
|
|
</p></div><p>
|
|||
|
|
If you're using a recent Mac with a
|
|||
|
|
<a class="link" href="https://www.apple.com/euro/mac/shared/docs/Apple_T2_Security_Chip_Overview.pdf" target="_top">T2 chip</a>,
|
|||
|
|
your drive will still be encrypted at rest (in which case "unencrypted"
|
|||
|
|
is a bit of a misnomer). To use this approach, just install Nix with:
|
|||
|
|
</p><pre class="screen">$ sh <(curl -L https://nixos.org/nix/install) --darwin-use-unencrypted-nix-store-volume</pre><p>
|
|||
|
|
If you don't like the sound of this, you'll want to weigh the
|
|||
|
|
other approaches and tradeoffs detailed in this section.
|
|||
|
|
</p><div class="note"><h3 class="title">Eventual solutions?</h3><p>
|
|||
|
|
All of the known workarounds have drawbacks, but we hope
|
|||
|
|
better solutions will be available in the future. Some that
|
|||
|
|
we have our eye on are:
|
|||
|
|
</p><div class="orderedlist"><ol class="orderedlist" type="1"><li class="listitem"><p>
|
|||
|
|
A true firmlink would enable the Nix store to live on the
|
|||
|
|
primary data volume without the build problems caused by
|
|||
|
|
the symlink approach. End users cannot currently
|
|||
|
|
create true firmlinks.
|
|||
|
|
</p></li><li class="listitem"><p>
|
|||
|
|
If the Nix store volume shared FileVault encryption
|
|||
|
|
with the primary data volume (probably by using the same
|
|||
|
|
volume group and role), FileVault encryption could be
|
|||
|
|
easily supported by the installer without requiring
|
|||
|
|
manual setup by each user.
|
|||
|
|
</p></li></ol></div></div><div class="section"><div class="titlepage"><div><div><h3 class="title"><a id="sect-macos-installation-change-store-prefix"></a>4.3.1. Change the Nix store path prefix</h3></div></div></div><p>
|
|||
|
|
Changing the default prefix for the Nix store is a simple
|
|||
|
|
approach which enables you to leave it on your root volume,
|
|||
|
|
where it can take full advantage of FileVault encryption if
|
|||
|
|
enabled. Unfortunately, this approach also opts your device out
|
|||
|
|
of some benefits that are enabled by using the same prefix
|
|||
|
|
across systems:
|
|||
|
|
|
|||
|
|
</p><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><p>
|
|||
|
|
Your system won't be able to take advantage of the binary
|
|||
|
|
cache (unless someone is able to stand up and support
|
|||
|
|
duplicate caching infrastructure), which means you'll
|
|||
|
|
spend more time waiting for builds.
|
|||
|
|
</p></li><li class="listitem"><p>
|
|||
|
|
It's harder to build and deploy packages to Linux systems.
|
|||
|
|
</p></li></ul></div><p>
|
|||
|
|
|
|||
|
|
|
|||
|
|
|
|||
|
|
It would also possible (and often requested) to just apply this
|
|||
|
|
change ecosystem-wide, but it's an intrusive process that has
|
|||
|
|
side effects we want to avoid for now.
|
|||
|
|
|
|||
|
|
</p><p>
|
|||
|
|
</p></div><div class="section"><div class="titlepage"><div><div><h3 class="title"><a id="sect-macos-installation-encrypted-volume"></a>4.3.2. Use a separate encrypted volume</h3></div></div></div><p>
|
|||
|
|
If you like, you can also add encryption to the recommended
|
|||
|
|
approach taken by the installer. You can do this by pre-creating
|
|||
|
|
an encrypted volume before you run the installer--or you can
|
|||
|
|
run the installer and encrypt the volume it creates later.
|
|||
|
|
|
|||
|
|
</p><p>
|
|||
|
|
In either case, adding encryption to a second volume isn't quite
|
|||
|
|
as simple as enabling FileVault for your boot volume. Before you
|
|||
|
|
dive in, there are a few things to weigh:
|
|||
|
|
</p><div class="orderedlist"><ol class="orderedlist" type="1"><li class="listitem"><p>
|
|||
|
|
The additional volume won't be encrypted with your existing
|
|||
|
|
FileVault key, so you'll need another mechanism to decrypt
|
|||
|
|
the volume.
|
|||
|
|
</p></li><li class="listitem"><p>
|
|||
|
|
You can store the password in Keychain to automatically
|
|||
|
|
decrypt the volume on boot--but it'll have to wait on Keychain
|
|||
|
|
and may not mount before your GUI apps restore. If any of
|
|||
|
|
your launchd agents or apps depend on Nix-installed software
|
|||
|
|
(for example, if you use a Nix-installed login shell), the
|
|||
|
|
restore may fail or break.
|
|||
|
|
</p><p>
|
|||
|
|
On a case-by-case basis, you may be able to work around this
|
|||
|
|
problem by using <span class="command"><strong>wait4path</strong></span> to block
|
|||
|
|
execution until your executable is available.
|
|||
|
|
</p><p>
|
|||
|
|
It's also possible to decrypt and mount the volume earlier
|
|||
|
|
with a login hook--but this mechanism appears to be
|
|||
|
|
deprecated and its future is unclear.
|
|||
|
|
</p></li><li class="listitem"><p>
|
|||
|
|
You can hard-code the password in the clear, so that your
|
|||
|
|
store volume can be decrypted before Keychain is available.
|
|||
|
|
</p></li></ol></div><p>
|
|||
|
|
If you are comfortable navigating these tradeoffs, you can encrypt the volume with
|
|||
|
|
something along the lines of:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">alice$ diskutil apfs enableFileVault /nix -user disk</pre></div><div class="section"><div class="titlepage"><div><div><h3 class="title"><a id="sect-macos-installation-symlink"></a>4.3.3. Symlink the Nix store to a custom location</h3></div></div></div><p>
|
|||
|
|
Another simple approach is using <code class="filename">/etc/synthetic.conf</code>
|
|||
|
|
to symlink the Nix store to the data volume. This option also
|
|||
|
|
enables your store to share any configured FileVault encryption.
|
|||
|
|
Unfortunately, builds that resolve the symlink may leak the
|
|||
|
|
canonical path or even fail.
|
|||
|
|
</p><p>
|
|||
|
|
Because of these downsides, we can't recommend this approach.
|
|||
|
|
</p></div><div class="section"><div class="titlepage"><div><div><h3 class="title"><a id="sect-macos-installation-recommended-notes"></a>4.3.4. Notes on the recommended approach</h3></div></div></div><p>
|
|||
|
|
This section goes into a little more detail on the recommended
|
|||
|
|
approach. You don't need to understand it to run the installer,
|
|||
|
|
but it can serve as a helpful reference if you run into trouble.
|
|||
|
|
</p><div class="orderedlist"><ol class="orderedlist" type="1"><li class="listitem"><p>
|
|||
|
|
In order to compose user-writable locations into the new
|
|||
|
|
read-only system root, Apple introduced a new concept called
|
|||
|
|
<code class="literal">firmlinks</code>, which it describes as a
|
|||
|
|
"bi-directional wormhole" between two filesystems. You can
|
|||
|
|
see the current firmlinks in <code class="filename">/usr/share/firmlinks</code>.
|
|||
|
|
Unfortunately, firmlinks aren't (currently?) user-configurable.
|
|||
|
|
</p><p>
|
|||
|
|
For special cases like NFS mount points or package manager roots,
|
|||
|
|
<a class="link" href="https://developer.apple.com/library/archive/documentation/System/Conceptual/ManPages_iPhoneOS/man5/synthetic.conf.5.html" target="_top">synthetic.conf(5)</a>
|
|||
|
|
supports limited user-controlled file-creation (of symlinks,
|
|||
|
|
and synthetic empty directories) at <code class="filename">/</code>.
|
|||
|
|
To create a synthetic empty directory for mounting at <code class="filename">/nix</code>,
|
|||
|
|
add the following line to <code class="filename">/etc/synthetic.conf</code>
|
|||
|
|
(create it if necessary):
|
|||
|
|
</p><pre class="screen">nix</pre></li><li class="listitem"><p>
|
|||
|
|
This configuration is applied at boot time, but you can use
|
|||
|
|
<span class="command"><strong>apfs.util</strong></span> to trigger creation (not deletion)
|
|||
|
|
of new entries without a reboot:
|
|||
|
|
</p><pre class="screen">alice$ /System/Library/Filesystems/apfs.fs/Contents/Resources/apfs.util -B</pre></li><li class="listitem"><p>
|
|||
|
|
Create the new APFS volume with diskutil:
|
|||
|
|
</p><pre class="screen">alice$ sudo diskutil apfs addVolume diskX APFS 'Nix Store' -mountpoint /nix</pre></li><li class="listitem"><p>
|
|||
|
|
Using <span class="command"><strong>vifs</strong></span>, add the new mount to
|
|||
|
|
<code class="filename">/etc/fstab</code>. If it doesn't already have
|
|||
|
|
other entries, it should look something like:
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
#
|
|||
|
|
# Warning - this file should only be modified with vifs(8)
|
|||
|
|
#
|
|||
|
|
# Failure to do so is unsupported and may be destructive.
|
|||
|
|
#
|
|||
|
|
LABEL=Nix\040Store /nix apfs rw,nobrowse
|
|||
|
|
</pre><p>
|
|||
|
|
The nobrowse setting will keep Spotlight from indexing this
|
|||
|
|
volume, and keep it from showing up on your desktop.
|
|||
|
|
</p></li></ol></div></div></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a id="sect-nix-install-pinned-version-url"></a>4.4. Installing a pinned Nix version from a URL</h2></div></div></div><p>
|
|||
|
|
NixOS.org hosts version-specific installation URLs for all Nix
|
|||
|
|
versions since 1.11.16, at
|
|||
|
|
<code class="literal">https://releases.nixos.org/nix/nix-<em class="replaceable"><code>version</code></em>/install</code>.
|
|||
|
|
</p><p>
|
|||
|
|
These install scripts can be used the same as the main
|
|||
|
|
NixOS.org installation script:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
sh <(curl -L https://nixos.org/nix/install)
|
|||
|
|
</pre><p>
|
|||
|
|
</p><p>
|
|||
|
|
In the same directory of the install script are sha256 sums, and
|
|||
|
|
gpg signature files.
|
|||
|
|
</p></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a id="sect-nix-install-binary-tarball"></a>4.5. Installing from a binary tarball</h2></div></div></div><p>
|
|||
|
|
You can also download a binary tarball that contains Nix and all
|
|||
|
|
its dependencies. (This is what the install script at
|
|||
|
|
<code class="uri">https://nixos.org/nix/install</code> does automatically.) You
|
|||
|
|
should unpack it somewhere (e.g. in <code class="filename">/tmp</code>),
|
|||
|
|
and then run the script named <span class="command"><strong>install</strong></span> inside
|
|||
|
|
the binary tarball:
|
|||
|
|
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
alice$ cd /tmp
|
|||
|
|
alice$ tar xfj nix-1.8-x86_64-darwin.tar.bz2
|
|||
|
|
alice$ cd nix-1.8-x86_64-darwin
|
|||
|
|
alice$ ./install
|
|||
|
|
</pre><p>
|
|||
|
|
</p><p>
|
|||
|
|
If you need to edit the multi-user installation script to use
|
|||
|
|
different group ID or a different user ID range, modify the
|
|||
|
|
variables set in the file named
|
|||
|
|
<code class="filename">install-multi-user</code>.
|
|||
|
|
</p></div></div><div class="chapter"><div class="titlepage"><div><div><h2 class="title"><a id="ch-installing-source"></a>Chapter 5. Installing Nix from Source</h2></div></div></div><p>If no binary package is available, you can download and compile
|
|||
|
|
a source distribution.</p><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a id="sec-prerequisites-source"></a>5.1. Prerequisites</h2></div></div></div><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><p>GNU Autoconf
|
|||
|
|
(<a class="link" href="https://www.gnu.org/software/autoconf/" target="_top">https://www.gnu.org/software/autoconf/</a>)
|
|||
|
|
and the autoconf-archive macro collection
|
|||
|
|
(<a class="link" href="https://www.gnu.org/software/autoconf-archive/" target="_top">https://www.gnu.org/software/autoconf-archive/</a>).
|
|||
|
|
These are only needed to run the bootstrap script, and are not necessary
|
|||
|
|
if your source distribution came with a pre-built
|
|||
|
|
<code class="literal">./configure</code> script.</p></li><li class="listitem"><p>GNU Make.</p></li><li class="listitem"><p>Bash Shell. The <code class="literal">./configure</code> script
|
|||
|
|
relies on bashisms, so Bash is required.</p></li><li class="listitem"><p>A version of GCC or Clang that supports C++17.</p></li><li class="listitem"><p><span class="command"><strong>pkg-config</strong></span> to locate
|
|||
|
|
dependencies. If your distribution does not provide it, you can get
|
|||
|
|
it from <a class="link" href="http://www.freedesktop.org/wiki/Software/pkg-config" target="_top">http://www.freedesktop.org/wiki/Software/pkg-config</a>.</p></li><li class="listitem"><p>The OpenSSL library to calculate cryptographic hashes.
|
|||
|
|
If your distribution does not provide it, you can get it from <a class="link" href="https://www.openssl.org" target="_top">https://www.openssl.org</a>.</p></li><li class="listitem"><p>The <code class="literal">libbrotlienc</code> and
|
|||
|
|
<code class="literal">libbrotlidec</code> libraries to provide implementation
|
|||
|
|
of the Brotli compression algorithm. They are available for download
|
|||
|
|
from the official repository <a class="link" href="https://github.com/google/brotli" target="_top">https://github.com/google/brotli</a>.</p></li><li class="listitem"><p>The bzip2 compressor program and the
|
|||
|
|
<code class="literal">libbz2</code> library. Thus you must have bzip2
|
|||
|
|
installed, including development headers and libraries. If your
|
|||
|
|
distribution does not provide these, you can obtain bzip2 from <a class="link" href="https://web.archive.org/web/20180624184756/http://www.bzip.org/" target="_top">https://web.archive.org/web/20180624184756/http://www.bzip.org/</a>.</p></li><li class="listitem"><p><code class="literal">liblzma</code>, which is provided by
|
|||
|
|
XZ Utils. If your distribution does not provide this, you can
|
|||
|
|
get it from <a class="link" href="https://tukaani.org/xz/" target="_top">https://tukaani.org/xz/</a>.</p></li><li class="listitem"><p>cURL and its library. If your distribution does not
|
|||
|
|
provide it, you can get it from <a class="link" href="https://curl.haxx.se/" target="_top">https://curl.haxx.se/</a>.</p></li><li class="listitem"><p>The SQLite embedded database library, version 3.6.19
|
|||
|
|
or higher. If your distribution does not provide it, please install
|
|||
|
|
it from <a class="link" href="http://www.sqlite.org/" target="_top">http://www.sqlite.org/</a>.</p></li><li class="listitem"><p>The <a class="link" href="http://www.hboehm.info/gc/" target="_top">Boehm
|
|||
|
|
garbage collector</a> to reduce the evaluator’s memory
|
|||
|
|
consumption (optional). To enable it, install
|
|||
|
|
<code class="literal">pkgconfig</code> and the Boehm garbage collector, and
|
|||
|
|
pass the flag <code class="option">--enable-gc</code> to
|
|||
|
|
<span class="command"><strong>configure</strong></span>.</p></li><li class="listitem"><p>The <code class="literal">boost</code> library of version
|
|||
|
|
1.66.0 or higher. It can be obtained from the official web site
|
|||
|
|
<a class="link" href="https://www.boost.org/" target="_top">https://www.boost.org/</a>.</p></li><li class="listitem"><p>The <code class="literal">editline</code> library of version
|
|||
|
|
1.14.0 or higher. It can be obtained from the its repository
|
|||
|
|
<a class="link" href="https://github.com/troglobit/editline" target="_top">https://github.com/troglobit/editline</a>.</p></li><li class="listitem"><p>The <span class="command"><strong>xmllint</strong></span> and
|
|||
|
|
<span class="command"><strong>xsltproc</strong></span> programs to build this manual and the
|
|||
|
|
man-pages. These are part of the <code class="literal">libxml2</code> and
|
|||
|
|
<code class="literal">libxslt</code> packages, respectively. You also need
|
|||
|
|
the <a class="link" href="http://docbook.sourceforge.net/projects/xsl/" target="_top">DocBook
|
|||
|
|
XSL stylesheets</a> and optionally the <a class="link" href="http://www.docbook.org/schemas/5x" target="_top"> DocBook 5.0 RELAX NG
|
|||
|
|
schemas</a>. Note that these are only required if you modify the
|
|||
|
|
manual sources or when you are building from the Git
|
|||
|
|
repository.</p></li><li class="listitem"><p>Recent versions of Bison and Flex to build the
|
|||
|
|
parser. (This is because Nix needs GLR support in Bison and
|
|||
|
|
reentrancy support in Flex.) For Bison, you need version 2.6, which
|
|||
|
|
can be obtained from the <a class="link" href="ftp://alpha.gnu.org/pub/gnu/bison" target="_top">GNU FTP
|
|||
|
|
server</a>. For Flex, you need version 2.5.35, which is
|
|||
|
|
available on <a class="link" href="http://lex.sourceforge.net/" target="_top">SourceForge</a>.
|
|||
|
|
Slightly older versions may also work, but ancient versions like the
|
|||
|
|
ubiquitous 2.5.4a won't. Note that these are only required if you
|
|||
|
|
modify the parser or when you are building from the Git
|
|||
|
|
repository.</p></li><li class="listitem"><p>The <code class="literal">libseccomp</code> is used to provide
|
|||
|
|
syscall filtering on Linux. This is an optional dependency and can
|
|||
|
|
be disabled passing a <code class="option">--disable-seccomp-sandboxing</code>
|
|||
|
|
option to the <span class="command"><strong>configure</strong></span> script (Not recommended
|
|||
|
|
unless your system doesn't support
|
|||
|
|
<code class="literal">libseccomp</code>). To get the library, visit <a class="link" href="https://github.com/seccomp/libseccomp" target="_top">https://github.com/seccomp/libseccomp</a>.</p></li></ul></div></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a id="sec-obtaining-source"></a>5.2. Obtaining a Source Distribution</h2></div></div></div><p>The source tarball of the most recent stable release can be
|
|||
|
|
downloaded from the <a class="link" href="http://nixos.org/nix/download.html" target="_top">Nix homepage</a>.
|
|||
|
|
You can also grab the <a class="link" href="http://hydra.nixos.org/job/nix/master/release/latest-finished#tabs-constituents" target="_top">most
|
|||
|
|
recent development release</a>.</p><p>Alternatively, the most recent sources of Nix can be obtained
|
|||
|
|
from its <a class="link" href="https://github.com/NixOS/nix" target="_top">Git
|
|||
|
|
repository</a>. For example, the following command will check out
|
|||
|
|
the latest revision into a directory called
|
|||
|
|
<code class="filename">nix</code>:</p><pre class="screen">
|
|||
|
|
$ git clone https://github.com/NixOS/nix</pre><p>Likewise, specific releases can be obtained from the <a class="link" href="https://github.com/NixOS/nix/tags" target="_top">tags</a> of the
|
|||
|
|
repository.</p></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a id="sec-building-source"></a>5.3. Building Nix from Source</h2></div></div></div><p>After unpacking or checking out the Nix sources, issue the
|
|||
|
|
following commands:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ ./configure <em class="replaceable"><code>options...</code></em>
|
|||
|
|
$ make
|
|||
|
|
$ make install</pre><p>
|
|||
|
|
|
|||
|
|
Nix requires GNU Make so you may need to invoke
|
|||
|
|
<span class="command"><strong>gmake</strong></span> instead.</p><p>When building from the Git repository, these should be preceded
|
|||
|
|
by the command:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ ./bootstrap.sh</pre><p>
|
|||
|
|
|
|||
|
|
</p><p>The installation path can be specified by passing the
|
|||
|
|
<code class="option">--prefix=<em class="replaceable"><code>prefix</code></em></code> to
|
|||
|
|
<span class="command"><strong>configure</strong></span>. The default installation directory is
|
|||
|
|
<code class="filename">/usr/local</code>. You can change this to any location
|
|||
|
|
you like. You must have write permission to the
|
|||
|
|
<em class="replaceable"><code>prefix</code></em> path.</p><p>Nix keeps its <span class="emphasis"><em>store</em></span> (the place where
|
|||
|
|
packages are stored) in <code class="filename">/nix/store</code> by default.
|
|||
|
|
This can be changed using
|
|||
|
|
<code class="option">--with-store-dir=<em class="replaceable"><code>path</code></em></code>.</p><div class="warning"><h3 class="title">Warning</h3><p>It is best <span class="emphasis"><em>not</em></span> to change the Nix
|
|||
|
|
store from its default, since doing so makes it impossible to use
|
|||
|
|
pre-built binaries from the standard Nixpkgs channels — that is, all
|
|||
|
|
packages will need to be built from source.</p></div><p>Nix keeps state (such as its database and log files) in
|
|||
|
|
<code class="filename">/nix/var</code> by default. This can be changed using
|
|||
|
|
<code class="option">--localstatedir=<em class="replaceable"><code>path</code></em></code>.</p></div></div><div class="chapter"><div class="titlepage"><div><div><h2 class="title"><a id="ch-nix-security"></a>Chapter 6. Security</h2></div></div></div><p>Nix has two basic security models. First, it can be used in
|
|||
|
|
“single-user mode”, which is similar to what most other package
|
|||
|
|
management tools do: there is a single user (typically <code class="systemitem">root</code>) who performs all package
|
|||
|
|
management operations. All other users can then use the installed
|
|||
|
|
packages, but they cannot perform package management operations
|
|||
|
|
themselves.</p><p>Alternatively, you can configure Nix in “multi-user mode”. In
|
|||
|
|
this model, all users can perform package management operations — for
|
|||
|
|
instance, every user can install software without requiring root
|
|||
|
|
privileges. Nix ensures that this is secure. For instance, it’s not
|
|||
|
|
possible for one user to overwrite a package used by another user with
|
|||
|
|
a Trojan horse.</p><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a id="sec-single-user"></a>6.1. Single-User Mode</h2></div></div></div><p>In single-user mode, all Nix operations that access the database
|
|||
|
|
in <code class="filename"><em class="replaceable"><code>prefix</code></em>/var/nix/db</code>
|
|||
|
|
or modify the Nix store in
|
|||
|
|
<code class="filename"><em class="replaceable"><code>prefix</code></em>/store</code> must be
|
|||
|
|
performed under the user ID that owns those directories. This is
|
|||
|
|
typically <code class="systemitem">root</code>. (If you
|
|||
|
|
install from RPM packages, that’s in fact the default ownership.)
|
|||
|
|
However, on single-user machines, it is often convenient to
|
|||
|
|
<span class="command"><strong>chown</strong></span> those directories to your normal user account
|
|||
|
|
so that you don’t have to <span class="command"><strong>su</strong></span> to <code class="systemitem">root</code> all the time.</p></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a id="ssec-multi-user"></a>6.2. Multi-User Mode</h2></div></div></div><p>To allow a Nix store to be shared safely among multiple users,
|
|||
|
|
it is important that users are not able to run builders that modify
|
|||
|
|
the Nix store or database in arbitrary ways, or that interfere with
|
|||
|
|
builds started by other users. If they could do so, they could
|
|||
|
|
install a Trojan horse in some package and compromise the accounts of
|
|||
|
|
other users.</p><p>To prevent this, the Nix store and database are owned by some
|
|||
|
|
privileged user (usually <code class="literal">root</code>) and builders are
|
|||
|
|
executed under special user accounts (usually named
|
|||
|
|
<code class="literal">nixbld1</code>, <code class="literal">nixbld2</code>, etc.). When a
|
|||
|
|
unprivileged user runs a Nix command, actions that operate on the Nix
|
|||
|
|
store (such as builds) are forwarded to a <span class="emphasis"><em>Nix
|
|||
|
|
daemon</em></span> running under the owner of the Nix store/database
|
|||
|
|
that performs the operation.</p><div class="note"><h3 class="title">Note</h3><p>Multi-user mode has one important limitation: only
|
|||
|
|
<code class="systemitem">root</code> and a set of trusted
|
|||
|
|
users specified in <code class="filename">nix.conf</code> can specify arbitrary
|
|||
|
|
binary caches. So while unprivileged users may install packages from
|
|||
|
|
arbitrary Nix expressions, they may not get pre-built
|
|||
|
|
binaries.</p></div><div class="simplesect"><div class="titlepage"><div><div><h3 class="title"><a id="idm139733301775792"></a>Setting up the build users</h3></div></div></div><p>The <span class="emphasis"><em>build users</em></span> are the special UIDs under
|
|||
|
|
which builds are performed. They should all be members of the
|
|||
|
|
<span class="emphasis"><em>build users group</em></span> <code class="literal">nixbld</code>.
|
|||
|
|
This group should have no other members. The build users should not
|
|||
|
|
be members of any other group. On Linux, you can create the group and
|
|||
|
|
users as follows:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ groupadd -r nixbld
|
|||
|
|
$ for n in $(seq 1 10); do useradd -c "Nix build user $n" \
|
|||
|
|
-d /var/empty -g nixbld -G nixbld -M -N -r -s "$(which nologin)" \
|
|||
|
|
nixbld$n; done
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
This creates 10 build users. There can never be more concurrent builds
|
|||
|
|
than the number of build users, so you may want to increase this if
|
|||
|
|
you expect to do many builds at the same time.</p></div><div class="simplesect"><div class="titlepage"><div><div><h3 class="title"><a id="idm139733301772240"></a>Running the daemon</h3></div></div></div><p>The <a class="link" href="#sec-nix-daemon" title="nix-daemon">Nix daemon</a> should be
|
|||
|
|
started as follows (as <code class="literal">root</code>):
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-daemon</pre><p>
|
|||
|
|
|
|||
|
|
You’ll want to put that line somewhere in your system’s boot
|
|||
|
|
scripts.</p><p>To let unprivileged users use the daemon, they should set the
|
|||
|
|
<a class="link" href="#envar-remote"><code class="envar">NIX_REMOTE</code> environment
|
|||
|
|
variable</a> to <code class="literal">daemon</code>. So you should put a
|
|||
|
|
line like
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
export NIX_REMOTE=daemon</pre><p>
|
|||
|
|
|
|||
|
|
into the users’ login scripts.</p></div><div class="simplesect"><div class="titlepage"><div><div><h3 class="title"><a id="idm139733301766816"></a>Restricting access</h3></div></div></div><p>To limit which users can perform Nix operations, you can use the
|
|||
|
|
permissions on the directory
|
|||
|
|
<code class="filename">/nix/var/nix/daemon-socket</code>. For instance, if you
|
|||
|
|
want to restrict the use of Nix to the members of a group called
|
|||
|
|
<code class="literal">nix-users</code>, do
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ chgrp nix-users /nix/var/nix/daemon-socket
|
|||
|
|
$ chmod ug=rwx,o= /nix/var/nix/daemon-socket
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
This way, users who are not in the <code class="literal">nix-users</code> group
|
|||
|
|
cannot connect to the Unix domain socket
|
|||
|
|
<code class="filename">/nix/var/nix/daemon-socket/socket</code>, so they cannot
|
|||
|
|
perform Nix operations.</p></div></div></div><div class="chapter"><div class="titlepage"><div><div><h2 class="title"><a id="ch-env-variables"></a>Chapter 7. Environment Variables</h2></div></div></div><p>To use Nix, some environment variables should be set. In
|
|||
|
|
particular, <code class="envar">PATH</code> should contain the directories
|
|||
|
|
<code class="filename"><em class="replaceable"><code>prefix</code></em>/bin</code> and
|
|||
|
|
<code class="filename">~/.nix-profile/bin</code>. The first directory contains
|
|||
|
|
the Nix tools themselves, while <code class="filename">~/.nix-profile</code> is
|
|||
|
|
a symbolic link to the current <span class="emphasis"><em>user environment</em></span>
|
|||
|
|
(an automatically generated package consisting of symlinks to
|
|||
|
|
installed packages). The simplest way to set the required environment
|
|||
|
|
variables is to include the file
|
|||
|
|
<code class="filename"><em class="replaceable"><code>prefix</code></em>/etc/profile.d/nix.sh</code>
|
|||
|
|
in your <code class="filename">~/.profile</code> (or similar), like this:</p><pre class="screen">
|
|||
|
|
source <em class="replaceable"><code>prefix</code></em>/etc/profile.d/nix.sh</pre><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a id="sec-nix-ssl-cert-file"></a>7.1. <code class="envar">NIX_SSL_CERT_FILE</code></h2></div></div></div><p>If you need to specify a custom certificate bundle to account
|
|||
|
|
for an HTTPS-intercepting man in the middle proxy, you must specify
|
|||
|
|
the path to the certificate bundle in the environment variable
|
|||
|
|
<code class="envar">NIX_SSL_CERT_FILE</code>.</p><p>If you don't specify a <code class="envar">NIX_SSL_CERT_FILE</code>
|
|||
|
|
manually, Nix will install and use its own certificate
|
|||
|
|
bundle.</p><div class="procedure"><ol class="procedure" type="1"><li class="step"><p>Set the environment variable and install Nix</p><pre class="screen">
|
|||
|
|
$ export NIX_SSL_CERT_FILE=/etc/ssl/my-certificate-bundle.crt
|
|||
|
|
$ sh <(curl -L https://nixos.org/nix/install)
|
|||
|
|
</pre></li><li class="step"><p>In the shell profile and rc files (for example,
|
|||
|
|
<code class="filename">/etc/bashrc</code>, <code class="filename">/etc/zshrc</code>),
|
|||
|
|
add the following line:</p><pre class="programlisting">
|
|||
|
|
export NIX_SSL_CERT_FILE=/etc/ssl/my-certificate-bundle.crt
|
|||
|
|
</pre></li></ol></div><div class="note"><h3 class="title">Note</h3><p>You must not add the export and then do the install, as
|
|||
|
|
the Nix installer will detect the presense of Nix configuration, and
|
|||
|
|
abort.</p></div><div class="section"><div class="titlepage"><div><div><h3 class="title"><a id="sec-nix-ssl-cert-file-with-nix-daemon-and-macos"></a>7.1.1. <code class="envar">NIX_SSL_CERT_FILE</code> with macOS and the Nix daemon</h3></div></div></div><p>On macOS you must specify the environment variable for the Nix
|
|||
|
|
daemon service, then restart it:</p><pre class="screen">
|
|||
|
|
$ sudo launchctl setenv NIX_SSL_CERT_FILE /etc/ssl/my-certificate-bundle.crt
|
|||
|
|
$ sudo launchctl kickstart -k system/org.nixos.nix-daemon
|
|||
|
|
</pre></div><div class="section"><div class="titlepage"><div><div><h3 class="title"><a id="sec-installer-proxy-settings"></a>7.1.2. Proxy Environment Variables</h3></div></div></div><p>The Nix installer has special handling for these proxy-related
|
|||
|
|
environment variables:
|
|||
|
|
<code class="varname">http_proxy</code>, <code class="varname">https_proxy</code>,
|
|||
|
|
<code class="varname">ftp_proxy</code>, <code class="varname">no_proxy</code>,
|
|||
|
|
<code class="varname">HTTP_PROXY</code>, <code class="varname">HTTPS_PROXY</code>,
|
|||
|
|
<code class="varname">FTP_PROXY</code>, <code class="varname">NO_PROXY</code>.
|
|||
|
|
</p><p>If any of these variables are set when running the Nix installer,
|
|||
|
|
then the installer will create an override file at
|
|||
|
|
<code class="filename">/etc/systemd/system/nix-daemon.service.d/override.conf</code>
|
|||
|
|
so <span class="command"><strong>nix-daemon</strong></span> will use them.
|
|||
|
|
</p></div></div></div></div><div class="chapter"><div class="titlepage"><div><div><h1 class="title"><a id="ch-upgrading-nix"></a>Chapter 8. Upgrading Nix</h1></div></div></div><p>
|
|||
|
|
Multi-user Nix users on macOS can upgrade Nix by running:
|
|||
|
|
<span class="command"><strong>sudo -i sh -c 'nix-channel --update &&
|
|||
|
|
nix-env -iA nixpkgs.nix &&
|
|||
|
|
launchctl remove org.nixos.nix-daemon &&
|
|||
|
|
launchctl load /Library/LaunchDaemons/org.nixos.nix-daemon.plist'</strong></span>
|
|||
|
|
</p><p>
|
|||
|
|
Single-user installations of Nix should run this:
|
|||
|
|
<span class="command"><strong>nix-channel --update; nix-env -iA nixpkgs.nix nixpkgs.cacert</strong></span>
|
|||
|
|
</p><p>
|
|||
|
|
Multi-user Nix users on Linux should run this with sudo:
|
|||
|
|
<span class="command"><strong>nix-channel --update; nix-env -iA nixpkgs.nix nixpkgs.cacert; systemctl daemon-reload; systemctl restart nix-daemon</strong></span>
|
|||
|
|
</p></div><div class="part"><div class="titlepage"><div><div><h1 class="title"><a id="chap-package-management"></a>Part III. Package Management</h1></div></div></div><div class="partintro"><div></div><p>This chapter discusses how to do package management with Nix,
|
|||
|
|
i.e., how to obtain, install, upgrade, and erase packages. This is
|
|||
|
|
the “user’s” perspective of the Nix system — people
|
|||
|
|
who want to <span class="emphasis"><em>create</em></span> packages should consult
|
|||
|
|
<a class="xref" href="#chap-writing-nix-expressions" title="Part IV. Writing Nix Expressions">Part IV, “Writing Nix Expressions”</a>.</p></div><div class="chapter"><div class="titlepage"><div><div><h2 class="title"><a id="ch-basic-package-mgmt"></a>Chapter 9. Basic Package Management</h2></div></div></div><p>The main command for package management is <a class="link" href="#sec-nix-env" title="nix-env"><span class="command"><strong>nix-env</strong></span></a>. You can use
|
|||
|
|
it to install, upgrade, and erase packages, and to query what
|
|||
|
|
packages are installed or are available for installation.</p><p>In Nix, different users can have different “views”
|
|||
|
|
on the set of installed applications. That is, there might be lots of
|
|||
|
|
applications present on the system (possibly in many different
|
|||
|
|
versions), but users can have a specific selection of those active —
|
|||
|
|
where “active” just means that it appears in a directory
|
|||
|
|
in the user’s <code class="envar">PATH</code>. Such a view on the set of
|
|||
|
|
installed applications is called a <span class="emphasis"><em>user
|
|||
|
|
environment</em></span>, which is just a directory tree consisting of
|
|||
|
|
symlinks to the files of the active applications. </p><p>Components are installed from a set of <span class="emphasis"><em>Nix
|
|||
|
|
expressions</em></span> that tell Nix how to build those packages,
|
|||
|
|
including, if necessary, their dependencies. There is a collection of
|
|||
|
|
Nix expressions called the Nixpkgs package collection that contains
|
|||
|
|
packages ranging from basic development stuff such as GCC and Glibc,
|
|||
|
|
to end-user applications like Mozilla Firefox. (Nix is however not
|
|||
|
|
tied to the Nixpkgs package collection; you could write your own Nix
|
|||
|
|
expressions based on Nixpkgs, or completely new ones.)</p><p>You can manually download the latest version of Nixpkgs from
|
|||
|
|
<a class="link" href="http://nixos.org/nixpkgs/download.html" target="_top">http://nixos.org/nixpkgs/download.html</a>. However,
|
|||
|
|
it’s much more convenient to use the Nixpkgs
|
|||
|
|
<span class="emphasis"><em>channel</em></span>, since it makes it easy to stay up to
|
|||
|
|
date with new versions of Nixpkgs. (Channels are described in more
|
|||
|
|
detail in <a class="xref" href="#sec-channels" title="Chapter 12. Channels">Chapter 12, <em>Channels</em></a>.) Nixpkgs is automatically
|
|||
|
|
added to your list of “subscribed” channels when you install
|
|||
|
|
Nix. If this is not the case for some reason, you can add it as
|
|||
|
|
follows:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-channel --add https://nixos.org/channels/nixpkgs-unstable
|
|||
|
|
$ nix-channel --update
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
</p><div class="note"><h3 class="title">Note</h3><p>On NixOS, you’re automatically subscribed to a NixOS
|
|||
|
|
channel corresponding to your NixOS major release
|
|||
|
|
(e.g. <code class="uri">http://nixos.org/channels/nixos-14.12</code>). A NixOS
|
|||
|
|
channel is identical to the Nixpkgs channel, except that it contains
|
|||
|
|
only Linux binaries and is updated only if a set of regression tests
|
|||
|
|
succeed.</p></div><p>You can view the set of available packages in Nixpkgs:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-env -qa
|
|||
|
|
aterm-2.2
|
|||
|
|
bash-3.0
|
|||
|
|
binutils-2.15
|
|||
|
|
bison-1.875d
|
|||
|
|
blackdown-1.4.2
|
|||
|
|
bzip2-1.0.2
|
|||
|
|
…</pre><p>
|
|||
|
|
|
|||
|
|
The flag <code class="option">-q</code> specifies a query operation, and
|
|||
|
|
<code class="option">-a</code> means that you want to show the “available” (i.e.,
|
|||
|
|
installable) packages, as opposed to the installed packages. If you
|
|||
|
|
downloaded Nixpkgs yourself, or if you checked it out from GitHub,
|
|||
|
|
then you need to pass the path to your Nixpkgs tree using the
|
|||
|
|
<code class="option">-f</code> flag:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-env -qaf <em class="replaceable"><code>/path/to/nixpkgs</code></em>
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
where <em class="replaceable"><code>/path/to/nixpkgs</code></em> is where you’ve
|
|||
|
|
unpacked or checked out Nixpkgs.</p><p>You can select specific packages by name:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-env -qa firefox
|
|||
|
|
firefox-34.0.5
|
|||
|
|
firefox-with-plugins-34.0.5
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
and using regular expressions:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-env -qa 'firefox.*'
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
</p><p>It is also possible to see the <span class="emphasis"><em>status</em></span> of
|
|||
|
|
available packages, i.e., whether they are installed into the user
|
|||
|
|
environment and/or present in the system:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-env -qas
|
|||
|
|
…
|
|||
|
|
-PS bash-3.0
|
|||
|
|
--S binutils-2.15
|
|||
|
|
IPS bison-1.875d
|
|||
|
|
…</pre><p>
|
|||
|
|
|
|||
|
|
The first character (<code class="literal">I</code>) indicates whether the
|
|||
|
|
package is installed in your current user environment. The second
|
|||
|
|
(<code class="literal">P</code>) indicates whether it is present on your system
|
|||
|
|
(in which case installing it into your user environment would be a
|
|||
|
|
very quick operation). The last one (<code class="literal">S</code>) indicates
|
|||
|
|
whether there is a so-called <span class="emphasis"><em>substitute</em></span> for the
|
|||
|
|
package, which is Nix’s mechanism for doing binary deployment. It
|
|||
|
|
just means that Nix knows that it can fetch a pre-built package from
|
|||
|
|
somewhere (typically a network server) instead of building it
|
|||
|
|
locally.</p><p>You can install a package using <code class="literal">nix-env -i</code>.
|
|||
|
|
For instance,
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-env -i subversion</pre><p>
|
|||
|
|
|
|||
|
|
will install the package called <code class="literal">subversion</code> (which
|
|||
|
|
is, of course, the <a class="link" href="http://subversion.tigris.org/" target="_top">Subversion version
|
|||
|
|
management system</a>).</p><div class="note"><h3 class="title">Note</h3><p>When you ask Nix to install a package, it will first try
|
|||
|
|
to get it in pre-compiled form from a <span class="emphasis"><em>binary
|
|||
|
|
cache</em></span>. By default, Nix will use the binary cache
|
|||
|
|
<code class="uri">https://cache.nixos.org</code>; it contains binaries for most
|
|||
|
|
packages in Nixpkgs. Only if no binary is available in the binary
|
|||
|
|
cache, Nix will build the package from source. So if <code class="literal">nix-env
|
|||
|
|
-i subversion</code> results in Nix building stuff from source,
|
|||
|
|
then either the package is not built for your platform by the Nixpkgs
|
|||
|
|
build servers, or your version of Nixpkgs is too old or too new. For
|
|||
|
|
instance, if you have a very recent checkout of Nixpkgs, then the
|
|||
|
|
Nixpkgs build servers may not have had a chance to build everything
|
|||
|
|
and upload the resulting binaries to
|
|||
|
|
<code class="uri">https://cache.nixos.org</code>. The Nixpkgs channel is only
|
|||
|
|
updated after all binaries have been uploaded to the cache, so if you
|
|||
|
|
stick to the Nixpkgs channel (rather than using a Git checkout of the
|
|||
|
|
Nixpkgs tree), you will get binaries for most packages.</p></div><p>Naturally, packages can also be uninstalled:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-env -e subversion</pre><p>
|
|||
|
|
|
|||
|
|
</p><p>Upgrading to a new version is just as easy. If you have a new
|
|||
|
|
release of Nix Packages, you can do:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-env -u subversion</pre><p>
|
|||
|
|
|
|||
|
|
This will <span class="emphasis"><em>only</em></span> upgrade Subversion if there is a
|
|||
|
|
“newer” version in the new set of Nix expressions, as
|
|||
|
|
defined by some pretty arbitrary rules regarding ordering of version
|
|||
|
|
numbers (which generally do what you’d expect of them). To just
|
|||
|
|
unconditionally replace Subversion with whatever version is in the Nix
|
|||
|
|
expressions, use <em class="parameter"><code>-i</code></em> instead of
|
|||
|
|
<em class="parameter"><code>-u</code></em>; <em class="parameter"><code>-i</code></em> will remove
|
|||
|
|
whatever version is already installed.</p><p>You can also upgrade all packages for which there are newer
|
|||
|
|
versions:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-env -u</pre><p>
|
|||
|
|
|
|||
|
|
</p><p>Sometimes it’s useful to be able to ask what
|
|||
|
|
<span class="command"><strong>nix-env</strong></span> would do, without actually doing it. For
|
|||
|
|
instance, to find out what packages would be upgraded by
|
|||
|
|
<code class="literal">nix-env -u</code>, you can do
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-env -u --dry-run
|
|||
|
|
(dry run; not doing anything)
|
|||
|
|
upgrading `libxslt-1.1.0' to `libxslt-1.1.10'
|
|||
|
|
upgrading `graphviz-1.10' to `graphviz-1.12'
|
|||
|
|
upgrading `coreutils-5.0' to `coreutils-5.2.1'</pre><p>
|
|||
|
|
|
|||
|
|
</p></div><div class="chapter"><div class="titlepage"><div><div><h2 class="title"><a id="sec-profiles"></a>Chapter 10. Profiles</h2></div></div></div><p>Profiles and user environments are Nix’s mechanism for
|
|||
|
|
implementing the ability to allow different users to have different
|
|||
|
|
configurations, and to do atomic upgrades and rollbacks. To
|
|||
|
|
understand how they work, it’s useful to know a bit about how Nix
|
|||
|
|
works. In Nix, packages are stored in unique locations in the
|
|||
|
|
<span class="emphasis"><em>Nix store</em></span> (typically,
|
|||
|
|
<code class="filename">/nix/store</code>). For instance, a particular version
|
|||
|
|
of the Subversion package might be stored in a directory
|
|||
|
|
<code class="filename">/nix/store/dpmvp969yhdqs7lm2r1a3gng7pyq6vy4-subversion-1.1.3/</code>,
|
|||
|
|
while another version might be stored in
|
|||
|
|
<code class="filename">/nix/store/5mq2jcn36ldlmh93yj1n8s9c95pj7c5s-subversion-1.1.2</code>.
|
|||
|
|
The long strings prefixed to the directory names are cryptographic
|
|||
|
|
hashes<a href="#ftn.idm139733301692864" class="footnote" id="idm139733301692864"><sup class="footnote">[1]</sup></a> of
|
|||
|
|
<span class="emphasis"><em>all</em></span> inputs involved in building the package —
|
|||
|
|
sources, dependencies, compiler flags, and so on. So if two
|
|||
|
|
packages differ in any way, they end up in different locations in
|
|||
|
|
the file system, so they don’t interfere with each other. <a class="xref" href="#fig-user-environments" title="Figure 10.1. User environments">Figure 10.1, “User environments”</a> shows a part of a typical Nix
|
|||
|
|
store.</p><div class="figure"><a id="fig-user-environments"></a><p class="title"><strong>Figure 10.1. User environments</strong></p><div class="figure-contents"><div class="mediaobject"><img src="figures/user-environments.png" alt="User environments" /></div></div></div><br class="figure-break" /><p>Of course, you wouldn’t want to type
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ /nix/store/dpmvp969yhdq...-subversion-1.1.3/bin/svn</pre><p>
|
|||
|
|
|
|||
|
|
every time you want to run Subversion. Of course we could set up the
|
|||
|
|
<code class="envar">PATH</code> environment variable to include the
|
|||
|
|
<code class="filename">bin</code> directory of every package we want to use,
|
|||
|
|
but this is not very convenient since changing <code class="envar">PATH</code>
|
|||
|
|
doesn’t take effect for already existing processes. The solution Nix
|
|||
|
|
uses is to create directory trees of symlinks to
|
|||
|
|
<span class="emphasis"><em>activated</em></span> packages. These are called
|
|||
|
|
<span class="emphasis"><em>user environments</em></span> and they are packages
|
|||
|
|
themselves (though automatically generated by
|
|||
|
|
<span class="command"><strong>nix-env</strong></span>), so they too reside in the Nix store. For
|
|||
|
|
instance, in <a class="xref" href="#fig-user-environments" title="Figure 10.1. User environments">Figure 10.1, “User environments”</a> the user
|
|||
|
|
environment <code class="filename">/nix/store/0c1p5z4kda11...-user-env</code>
|
|||
|
|
contains a symlink to just Subversion 1.1.2 (arrows in the figure
|
|||
|
|
indicate symlinks). This would be what we would obtain if we had done
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-env -i subversion</pre><p>
|
|||
|
|
|
|||
|
|
on a set of Nix expressions that contained Subversion 1.1.2.</p><p>This doesn’t in itself solve the problem, of course; you
|
|||
|
|
wouldn’t want to type
|
|||
|
|
<code class="filename">/nix/store/0c1p5z4kda11...-user-env/bin/svn</code>
|
|||
|
|
either. That’s why there are symlinks outside of the store that point
|
|||
|
|
to the user environments in the store; for instance, the symlinks
|
|||
|
|
<code class="filename">default-42-link</code> and
|
|||
|
|
<code class="filename">default-43-link</code> in the example. These are called
|
|||
|
|
<span class="emphasis"><em>generations</em></span> since every time you perform a
|
|||
|
|
<span class="command"><strong>nix-env</strong></span> operation, a new user environment is
|
|||
|
|
generated based on the current one. For instance, generation 43 was
|
|||
|
|
created from generation 42 when we did
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-env -i subversion firefox</pre><p>
|
|||
|
|
|
|||
|
|
on a set of Nix expressions that contained Firefox and a new version
|
|||
|
|
of Subversion.</p><p>Generations are grouped together into
|
|||
|
|
<span class="emphasis"><em>profiles</em></span> so that different users don’t interfere
|
|||
|
|
with each other if they don’t want to. For example:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ ls -l /nix/var/nix/profiles/
|
|||
|
|
...
|
|||
|
|
lrwxrwxrwx 1 eelco ... default-42-link -> /nix/store/0c1p5z4kda11...-user-env
|
|||
|
|
lrwxrwxrwx 1 eelco ... default-43-link -> /nix/store/3aw2pdyx2jfc...-user-env
|
|||
|
|
lrwxrwxrwx 1 eelco ... default -> default-43-link</pre><p>
|
|||
|
|
|
|||
|
|
This shows a profile called <code class="filename">default</code>. The file
|
|||
|
|
<code class="filename">default</code> itself is actually a symlink that points
|
|||
|
|
to the current generation. When we do a <span class="command"><strong>nix-env</strong></span>
|
|||
|
|
operation, a new user environment and generation link are created
|
|||
|
|
based on the current one, and finally the <code class="filename">default</code>
|
|||
|
|
symlink is made to point at the new generation. This last step is
|
|||
|
|
atomic on Unix, which explains how we can do atomic upgrades. (Note
|
|||
|
|
that the building/installing of new packages doesn’t interfere in
|
|||
|
|
any way with old packages, since they are stored in different
|
|||
|
|
locations in the Nix store.)</p><p>If you find that you want to undo a <span class="command"><strong>nix-env</strong></span>
|
|||
|
|
operation, you can just do
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-env --rollback</pre><p>
|
|||
|
|
|
|||
|
|
which will just make the current generation link point at the previous
|
|||
|
|
link. E.g., <code class="filename">default</code> would be made to point at
|
|||
|
|
<code class="filename">default-42-link</code>. You can also switch to a
|
|||
|
|
specific generation:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-env --switch-generation 43</pre><p>
|
|||
|
|
|
|||
|
|
which in this example would roll forward to generation 43 again. You
|
|||
|
|
can also see all available generations:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-env --list-generations</pre><p>You generally wouldn’t have
|
|||
|
|
<code class="filename">/nix/var/nix/profiles/<em class="replaceable"><code>some-profile</code></em>/bin</code>
|
|||
|
|
in your <code class="envar">PATH</code>. Rather, there is a symlink
|
|||
|
|
<code class="filename">~/.nix-profile</code> that points to your current
|
|||
|
|
profile. This means that you should put
|
|||
|
|
<code class="filename">~/.nix-profile/bin</code> in your <code class="envar">PATH</code>
|
|||
|
|
(and indeed, that’s what the initialisation script
|
|||
|
|
<code class="filename">/nix/etc/profile.d/nix.sh</code> does). This makes it
|
|||
|
|
easier to switch to a different profile. You can do that using the
|
|||
|
|
command <span class="command"><strong>nix-env --switch-profile</strong></span>:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-env --switch-profile /nix/var/nix/profiles/my-profile
|
|||
|
|
|
|||
|
|
$ nix-env --switch-profile /nix/var/nix/profiles/default</pre><p>
|
|||
|
|
|
|||
|
|
These commands switch to the <code class="filename">my-profile</code> and
|
|||
|
|
default profile, respectively. If the profile doesn’t exist, it will
|
|||
|
|
be created automatically. You should be careful about storing a
|
|||
|
|
profile in another location than the <code class="filename">profiles</code>
|
|||
|
|
directory, since otherwise it might not be used as a root of the
|
|||
|
|
garbage collector (see <a class="xref" href="#sec-garbage-collection" title="Chapter 11. Garbage Collection">Chapter 11, <em>Garbage Collection</em></a>).</p><p>All <span class="command"><strong>nix-env</strong></span> operations work on the profile
|
|||
|
|
pointed to by <span class="command"><strong>~/.nix-profile</strong></span>, but you can override
|
|||
|
|
this using the <code class="option">--profile</code> option (abbreviation
|
|||
|
|
<code class="option">-p</code>):
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-env -p /nix/var/nix/profiles/other-profile -i subversion</pre><p>
|
|||
|
|
|
|||
|
|
This will <span class="emphasis"><em>not</em></span> change the
|
|||
|
|
<span class="command"><strong>~/.nix-profile</strong></span> symlink.</p><div class="footnotes"><br /><hr style="width:100; text-align:left;margin-left: 0" /><div id="ftn.idm139733301692864" class="footnote"><p><a href="#idm139733301692864" class="para"><sup class="para">[1] </sup></a>160-bit truncations of SHA-256 hashes encoded in
|
|||
|
|
a base-32 notation, to be precise.</p></div></div></div><div class="chapter"><div class="titlepage"><div><div><h2 class="title"><a id="sec-garbage-collection"></a>Chapter 11. Garbage Collection</h2></div></div></div><p><span class="command"><strong>nix-env</strong></span> operations such as upgrades
|
|||
|
|
(<code class="option">-u</code>) and uninstall (<code class="option">-e</code>) never
|
|||
|
|
actually delete packages from the system. All they do (as shown
|
|||
|
|
above) is to create a new user environment that no longer contains
|
|||
|
|
symlinks to the “deleted” packages.</p><p>Of course, since disk space is not infinite, unused packages
|
|||
|
|
should be removed at some point. You can do this by running the Nix
|
|||
|
|
garbage collector. It will remove from the Nix store any package
|
|||
|
|
not used (directly or indirectly) by any generation of any
|
|||
|
|
profile.</p><p>Note however that as long as old generations reference a
|
|||
|
|
package, it will not be deleted. After all, we wouldn’t be able to
|
|||
|
|
do a rollback otherwise. So in order for garbage collection to be
|
|||
|
|
effective, you should also delete (some) old generations. Of course,
|
|||
|
|
this should only be done if you are certain that you will not need to
|
|||
|
|
roll back.</p><p>To delete all old (non-current) generations of your current
|
|||
|
|
profile:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-env --delete-generations old</pre><p>
|
|||
|
|
|
|||
|
|
Instead of <code class="literal">old</code> you can also specify a list of
|
|||
|
|
generations, e.g.,
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-env --delete-generations 10 11 14</pre><p>
|
|||
|
|
|
|||
|
|
To delete all generations older than a specified number of days
|
|||
|
|
(except the current generation), use the <code class="literal">d</code>
|
|||
|
|
suffix. For example,
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-env --delete-generations 14d</pre><p>
|
|||
|
|
|
|||
|
|
deletes all generations older than two weeks.</p><p>After removing appropriate old generations you can run the
|
|||
|
|
garbage collector as follows:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-store --gc</pre><p>
|
|||
|
|
|
|||
|
|
The behaviour of the gargage collector is affected by the
|
|||
|
|
<code class="literal">keep-derivations</code> (default: true) and <code class="literal">keep-outputs</code>
|
|||
|
|
(default: false) options in the Nix configuration file. The defaults will ensure
|
|||
|
|
that all derivations that are build-time dependencies of garbage collector roots
|
|||
|
|
will be kept and that all output paths that are runtime dependencies
|
|||
|
|
will be kept as well. All other derivations or paths will be collected.
|
|||
|
|
(This is usually what you want, but while you are developing
|
|||
|
|
it may make sense to keep outputs to ensure that rebuild times are quick.)
|
|||
|
|
|
|||
|
|
If you are feeling uncertain, you can also first view what files would
|
|||
|
|
be deleted:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-store --gc --print-dead</pre><p>
|
|||
|
|
|
|||
|
|
Likewise, the option <code class="option">--print-live</code> will show the paths
|
|||
|
|
that <span class="emphasis"><em>won’t</em></span> be deleted.</p><p>There is also a convenient little utility
|
|||
|
|
<span class="command"><strong>nix-collect-garbage</strong></span>, which when invoked with the
|
|||
|
|
<code class="option">-d</code> (<code class="option">--delete-old</code>) switch deletes all
|
|||
|
|
old generations of all profiles in
|
|||
|
|
<code class="filename">/nix/var/nix/profiles</code>. So
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-collect-garbage -d</pre><p>
|
|||
|
|
|
|||
|
|
is a quick and easy way to clean up your system.</p><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a id="ssec-gc-roots"></a>11.1. Garbage Collector Roots</h2></div></div></div><p>The roots of the garbage collector are all store paths to which
|
|||
|
|
there are symlinks in the directory
|
|||
|
|
<code class="filename"><em class="replaceable"><code>prefix</code></em>/nix/var/nix/gcroots</code>.
|
|||
|
|
For instance, the following command makes the path
|
|||
|
|
<code class="filename">/nix/store/d718ef...-foo</code> a root of the collector:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ ln -s /nix/store/d718ef...-foo /nix/var/nix/gcroots/bar</pre><p>
|
|||
|
|
|
|||
|
|
That is, after this command, the garbage collector will not remove
|
|||
|
|
<code class="filename">/nix/store/d718ef...-foo</code> or any of its
|
|||
|
|
dependencies.</p><p>Subdirectories of
|
|||
|
|
<code class="filename"><em class="replaceable"><code>prefix</code></em>/nix/var/nix/gcroots</code>
|
|||
|
|
are also searched for symlinks. Symlinks to non-store paths are
|
|||
|
|
followed and searched for roots, but symlinks to non-store paths
|
|||
|
|
<span class="emphasis"><em>inside</em></span> the paths reached in that way are not
|
|||
|
|
followed to prevent infinite recursion.</p></div></div><div class="chapter"><div class="titlepage"><div><div><h2 class="title"><a id="sec-channels"></a>Chapter 12. Channels</h2></div></div></div><p>If you want to stay up to date with a set of packages, it’s not
|
|||
|
|
very convenient to manually download the latest set of Nix expressions
|
|||
|
|
for those packages and upgrade using <span class="command"><strong>nix-env</strong></span>.
|
|||
|
|
Fortunately, there’s a better way: <span class="emphasis"><em>Nix
|
|||
|
|
channels</em></span>.</p><p>A Nix channel is just a URL that points to a place that contains
|
|||
|
|
a set of Nix expressions and a manifest. Using the command <a class="link" href="#sec-nix-channel" title="nix-channel"><span class="command"><strong>nix-channel</strong></span></a> you
|
|||
|
|
can automatically stay up to date with whatever is available at that
|
|||
|
|
URL.</p><p>To see the list of official NixOS channels, visit <a class="link" href="https://nixos.org/channels" target="_top">https://nixos.org/channels</a>.</p><p>You can “subscribe” to a channel using
|
|||
|
|
<span class="command"><strong>nix-channel --add</strong></span>, e.g.,
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-channel --add https://nixos.org/channels/nixpkgs-unstable</pre><p>
|
|||
|
|
|
|||
|
|
subscribes you to a channel that always contains that latest version
|
|||
|
|
of the Nix Packages collection. (Subscribing really just means that
|
|||
|
|
the URL is added to the file <code class="filename">~/.nix-channels</code>,
|
|||
|
|
where it is read by subsequent calls to <span class="command"><strong>nix-channel
|
|||
|
|
--update</strong></span>.) You can “unsubscribe” using <span class="command"><strong>nix-channel
|
|||
|
|
--remove</strong></span>:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-channel --remove nixpkgs
|
|||
|
|
</pre><p>
|
|||
|
|
</p><p>To obtain the latest Nix expressions available in a channel, do
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-channel --update</pre><p>
|
|||
|
|
|
|||
|
|
This downloads and unpacks the Nix expressions in every channel
|
|||
|
|
(downloaded from <code class="literal"><em class="replaceable"><code>url</code></em>/nixexprs.tar.bz2</code>).
|
|||
|
|
It also makes the union of each channel’s Nix expressions available by
|
|||
|
|
default to <span class="command"><strong>nix-env</strong></span> operations (via the symlink
|
|||
|
|
<code class="filename">~/.nix-defexpr/channels</code>). Consequently, you can
|
|||
|
|
then say
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-env -u</pre><p>
|
|||
|
|
|
|||
|
|
to upgrade all packages in your profile to the latest versions
|
|||
|
|
available in the subscribed channels.</p></div><div class="chapter"><div class="titlepage"><div><div><h2 class="title"><a id="sec-sharing-packages"></a>Chapter 13. Sharing Packages Between Machines</h2></div></div></div><p>Sometimes you want to copy a package from one machine to
|
|||
|
|
another. Or, you want to install some packages and you know that
|
|||
|
|
another machine already has some or all of those packages or their
|
|||
|
|
dependencies. In that case there are mechanisms to quickly copy
|
|||
|
|
packages between machines.</p><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a id="ssec-binary-cache-substituter"></a>13.1. Serving a Nix store via HTTP</h2></div></div></div><p>You can easily share the Nix store of a machine via HTTP. This
|
|||
|
|
allows other machines to fetch store paths from that machine to speed
|
|||
|
|
up installations. It uses the same <span class="emphasis"><em>binary cache</em></span>
|
|||
|
|
mechanism that Nix usually uses to fetch pre-built binaries from
|
|||
|
|
<code class="uri">https://cache.nixos.org</code>.</p><p>The daemon that handles binary cache requests via HTTP,
|
|||
|
|
<span class="command"><strong>nix-serve</strong></span>, is not part of the Nix distribution, but
|
|||
|
|
you can install it from Nixpkgs:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-env -i nix-serve
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
You can then start the server, listening for HTTP connections on
|
|||
|
|
whatever port you like:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-serve -p 8080
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
To check whether it works, try the following on the client:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ curl http://avalon:8080/nix-cache-info
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
which should print something like:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
StoreDir: /nix/store
|
|||
|
|
WantMassQuery: 1
|
|||
|
|
Priority: 30
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
</p><p>On the client side, you can tell Nix to use your binary cache
|
|||
|
|
using <code class="option">--option extra-binary-caches</code>, e.g.:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-env -i firefox --option extra-binary-caches http://avalon:8080/
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
The option <code class="option">extra-binary-caches</code> tells Nix to use this
|
|||
|
|
binary cache in addition to your default caches, such as
|
|||
|
|
<code class="uri">https://cache.nixos.org</code>. Thus, for any path in the closure
|
|||
|
|
of Firefox, Nix will first check if the path is available on the
|
|||
|
|
server <code class="literal">avalon</code> or another binary caches. If not, it
|
|||
|
|
will fall back to building from source.</p><p>You can also tell Nix to always use your binary cache by adding
|
|||
|
|
a line to the <code class="filename"><a class="filename" href="#sec-conf-file" title="nix.conf">nix.conf</a></code>
|
|||
|
|
configuration file like this:
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
binary-caches = http://avalon:8080/ https://cache.nixos.org/
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
</p></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a id="ssec-copy-closure"></a>13.2. Copying Closures Via SSH</h2></div></div></div><p>The command <span class="command"><strong><a class="command" href="#sec-nix-copy-closure" title="nix-copy-closure">nix-copy-closure</a></strong></span> copies a Nix
|
|||
|
|
store path along with all its dependencies to or from another machine
|
|||
|
|
via the SSH protocol. It doesn’t copy store paths that are already
|
|||
|
|
present on the target machine. For example, the following command
|
|||
|
|
copies Firefox with all its dependencies:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-copy-closure --to alice@itchy.example.org $(type -p firefox)</pre><p>
|
|||
|
|
|
|||
|
|
See <a class="xref" href="#sec-nix-copy-closure" title="nix-copy-closure"><span class="refentrytitle">nix-copy-closure</span>(1)</a> for details.</p><p>With <span class="command"><strong><a class="command" href="#refsec-nix-store-export" title="Operation --export">nix-store
|
|||
|
|
--export</a></strong></span> and <span class="command"><strong><a class="command" href="#refsec-nix-store-import" title="Operation --import">nix-store --import</a></strong></span> you can
|
|||
|
|
write the closure of a store path (that is, the path and all its
|
|||
|
|
dependencies) to a file, and then unpack that file into another Nix
|
|||
|
|
store. For example,
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-store --export $(nix-store -qR $(type -p firefox)) > firefox.closure</pre><p>
|
|||
|
|
|
|||
|
|
writes the closure of Firefox to a file. You can then copy this file
|
|||
|
|
to another machine and install the closure:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-store --import < firefox.closure</pre><p>
|
|||
|
|
|
|||
|
|
Any store paths in the closure that are already present in the target
|
|||
|
|
store are ignored. It is also possible to pipe the export into
|
|||
|
|
another command, e.g. to copy and install a closure directly to/on
|
|||
|
|
another machine:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-store --export $(nix-store -qR $(type -p firefox)) | bzip2 | \
|
|||
|
|
ssh alice@itchy.example.org "bunzip2 | nix-store --import"</pre><p>
|
|||
|
|
|
|||
|
|
However, <span class="command"><strong>nix-copy-closure</strong></span> is generally more
|
|||
|
|
efficient because it only copies paths that are not already present in
|
|||
|
|
the target Nix store.</p></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a id="ssec-ssh-substituter"></a>13.3. Serving a Nix store via SSH</h2></div></div></div><p>You can tell Nix to automatically fetch needed binaries from a
|
|||
|
|
remote Nix store via SSH. For example, the following installs Firefox,
|
|||
|
|
automatically fetching any store paths in Firefox’s closure if they
|
|||
|
|
are available on the server <code class="literal">avalon</code>:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-env -i firefox --substituters ssh://alice@avalon
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
This works similar to the binary cache substituter that Nix usually
|
|||
|
|
uses, only using SSH instead of HTTP: if a store path
|
|||
|
|
<code class="literal">P</code> is needed, Nix will first check if it’s available
|
|||
|
|
in the Nix store on <code class="literal">avalon</code>. If not, it will fall
|
|||
|
|
back to using the binary cache substituter, and then to building from
|
|||
|
|
source.</p><div class="note"><h3 class="title">Note</h3><p>The SSH substituter currently does not allow you to enter
|
|||
|
|
an SSH passphrase interactively. Therefore, you should use
|
|||
|
|
<span class="command"><strong>ssh-add</strong></span> to load the decrypted private key into
|
|||
|
|
<span class="command"><strong>ssh-agent</strong></span>.</p></div><p>You can also copy the closure of some store path, without
|
|||
|
|
installing it into your profile, e.g.
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-store -r /nix/store/m85bxg…-firefox-34.0.5 --substituters ssh://alice@avalon
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
This is essentially equivalent to doing
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-copy-closure --from alice@avalon /nix/store/m85bxg…-firefox-34.0.5
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
</p><p>You can use SSH’s <span class="emphasis"><em>forced command</em></span> feature to
|
|||
|
|
set up a restricted user account for SSH substituter access, allowing
|
|||
|
|
read-only access to the local Nix store, but nothing more. For
|
|||
|
|
example, add the following lines to <code class="filename">sshd_config</code>
|
|||
|
|
to restrict the user <code class="literal">nix-ssh</code>:
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
Match User nix-ssh
|
|||
|
|
AllowAgentForwarding no
|
|||
|
|
AllowTcpForwarding no
|
|||
|
|
PermitTTY no
|
|||
|
|
PermitTunnel no
|
|||
|
|
X11Forwarding no
|
|||
|
|
ForceCommand nix-store --serve
|
|||
|
|
Match All
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
On NixOS, you can accomplish the same by adding the following to your
|
|||
|
|
<code class="filename">configuration.nix</code>:
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
nix.sshServe.enable = true;
|
|||
|
|
nix.sshServe.keys = [ "ssh-dss AAAAB3NzaC1k... bob@example.org" ];
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
where the latter line lists the public keys of users that are allowed
|
|||
|
|
to connect.</p></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a id="ssec-s3-substituter"></a>13.4. Serving a Nix store via AWS S3 or S3-compatible Service</h2></div></div></div><p>Nix has built-in support for storing and fetching store paths
|
|||
|
|
from Amazon S3 and S3 compatible services. This uses the same
|
|||
|
|
<span class="emphasis"><em>binary</em></span> cache mechanism that Nix usually uses to
|
|||
|
|
fetch prebuilt binaries from <code class="uri">cache.nixos.org</code>.</p><p>The following options can be specified as URL parameters to
|
|||
|
|
the S3 URL:</p><div class="variablelist"><dl class="variablelist"><dt><span class="term"><code class="literal">profile</code></span></dt><dd><p>
|
|||
|
|
The name of the AWS configuration profile to use. By default
|
|||
|
|
Nix will use the <code class="literal">default</code> profile.
|
|||
|
|
</p></dd><dt><span class="term"><code class="literal">region</code></span></dt><dd><p>
|
|||
|
|
The region of the S3 bucket. <code class="literal">us–east-1</code> by
|
|||
|
|
default.
|
|||
|
|
</p><p>
|
|||
|
|
If your bucket is not in <code class="literal">us–east-1</code>, you
|
|||
|
|
should always explicitly specify the region parameter.
|
|||
|
|
</p></dd><dt><span class="term"><code class="literal">endpoint</code></span></dt><dd><p>
|
|||
|
|
The URL to your S3-compatible service, for when not using
|
|||
|
|
Amazon S3. Do not specify this value if you're using Amazon
|
|||
|
|
S3.
|
|||
|
|
</p><div class="note"><h3 class="title">Note</h3><p>This endpoint must support HTTPS and will use
|
|||
|
|
path-based addressing instead of virtual host based
|
|||
|
|
addressing.</p></div></dd><dt><span class="term"><code class="literal">scheme</code></span></dt><dd><p>
|
|||
|
|
The scheme used for S3 requests, <code class="literal">https</code>
|
|||
|
|
(default) or <code class="literal">http</code>. This option allows you to
|
|||
|
|
disable HTTPS for binary caches which don't support it.
|
|||
|
|
</p><div class="note"><h3 class="title">Note</h3><p>HTTPS should be used if the cache might contain
|
|||
|
|
sensitive information.</p></div></dd></dl></div><p>In this example we will use the bucket named
|
|||
|
|
<code class="literal">example-nix-cache</code>.</p><div class="section"><div class="titlepage"><div><div><h3 class="title"><a id="ssec-s3-substituter-anonymous-reads"></a>13.4.1. Anonymous Reads to your S3-compatible binary cache</h3></div></div></div><p>If your binary cache is publicly accessible and does not
|
|||
|
|
require authentication, the simplest and easiest way to use Nix with
|
|||
|
|
your S3 compatible binary cache is to use the HTTP URL for that
|
|||
|
|
cache.</p><p>For AWS S3 the binary cache URL for example bucket will be
|
|||
|
|
exactly <code class="uri">https://example-nix-cache.s3.amazonaws.com</code> or
|
|||
|
|
<code class="uri">s3://example-nix-cache</code>. For S3 compatible binary caches,
|
|||
|
|
consult that cache's documentation.</p><p>Your bucket will need the following bucket policy:</p><pre class="programlisting">
|
|||
|
|
{
|
|||
|
|
"Id": "DirectReads",
|
|||
|
|
"Version": "2012-10-17",
|
|||
|
|
"Statement": [
|
|||
|
|
{
|
|||
|
|
"Sid": "AllowDirectReads",
|
|||
|
|
"Action": [
|
|||
|
|
"s3:GetObject",
|
|||
|
|
"s3:GetBucketLocation"
|
|||
|
|
],
|
|||
|
|
"Effect": "Allow",
|
|||
|
|
"Resource": [
|
|||
|
|
"arn:aws:s3:::example-nix-cache",
|
|||
|
|
"arn:aws:s3:::example-nix-cache/*"
|
|||
|
|
],
|
|||
|
|
"Principal": "*"
|
|||
|
|
}
|
|||
|
|
]
|
|||
|
|
}
|
|||
|
|
</pre></div><div class="section"><div class="titlepage"><div><div><h3 class="title"><a id="ssec-s3-substituter-authenticated-reads"></a>13.4.2. Authenticated Reads to your S3 binary cache</h3></div></div></div><p>For AWS S3 the binary cache URL for example bucket will be
|
|||
|
|
exactly <code class="uri">s3://example-nix-cache</code>.</p><p>Nix will use the <a class="link" href="https://docs.aws.amazon.com/sdk-for-cpp/v1/developer-guide/credentials.html" target="_top">default
|
|||
|
|
credential provider chain</a> for authenticating requests to
|
|||
|
|
Amazon S3.</p><p>Nix supports authenticated reads from Amazon S3 and S3
|
|||
|
|
compatible binary caches.</p><p>Your bucket will need a bucket policy allowing the desired
|
|||
|
|
users to perform the <code class="literal">s3:GetObject</code> and
|
|||
|
|
<code class="literal">s3:GetBucketLocation</code> action on all objects in the
|
|||
|
|
bucket. The anonymous policy in <a class="xref" href="#ssec-s3-substituter-anonymous-reads" title="13.4.1. Anonymous Reads to your S3-compatible binary cache">Section 13.4.1, “Anonymous Reads to your S3-compatible binary cache”</a> can be updated to
|
|||
|
|
have a restricted <code class="literal">Principal</code> to support
|
|||
|
|
this.</p></div><div class="section"><div class="titlepage"><div><div><h3 class="title"><a id="ssec-s3-substituter-authenticated-writes"></a>13.4.3. Authenticated Writes to your S3-compatible binary cache</h3></div></div></div><p>Nix support fully supports writing to Amazon S3 and S3
|
|||
|
|
compatible buckets. The binary cache URL for our example bucket will
|
|||
|
|
be <code class="uri">s3://example-nix-cache</code>.</p><p>Nix will use the <a class="link" href="https://docs.aws.amazon.com/sdk-for-cpp/v1/developer-guide/credentials.html" target="_top">default
|
|||
|
|
credential provider chain</a> for authenticating requests to
|
|||
|
|
Amazon S3.</p><p>Your account will need the following IAM policy to
|
|||
|
|
upload to the cache:</p><pre class="programlisting">
|
|||
|
|
{
|
|||
|
|
"Version": "2012-10-17",
|
|||
|
|
"Statement": [
|
|||
|
|
{
|
|||
|
|
"Sid": "UploadToCache",
|
|||
|
|
"Effect": "Allow",
|
|||
|
|
"Action": [
|
|||
|
|
"s3:AbortMultipartUpload",
|
|||
|
|
"s3:GetBucketLocation",
|
|||
|
|
"s3:GetObject",
|
|||
|
|
"s3:ListBucket",
|
|||
|
|
"s3:ListBucketMultipartUploads",
|
|||
|
|
"s3:ListMultipartUploadParts",
|
|||
|
|
"s3:PutObject"
|
|||
|
|
],
|
|||
|
|
"Resource": [
|
|||
|
|
"arn:aws:s3:::example-nix-cache",
|
|||
|
|
"arn:aws:s3:::example-nix-cache/*"
|
|||
|
|
]
|
|||
|
|
}
|
|||
|
|
]
|
|||
|
|
}
|
|||
|
|
</pre><div class="example"><a id="idm139733301558256"></a><p class="title"><strong>Example 13.1. Uploading with a specific credential profile for Amazon S3</strong></p><div class="example-contents"><p><span class="command"><strong>nix copy --to 's3://example-nix-cache?profile=cache-upload&region=eu-west-2' nixpkgs.hello</strong></span></p></div></div><br class="example-break" /><div class="example"><a id="idm139733301556896"></a><p class="title"><strong>Example 13.2. Uploading to an S3-Compatible Binary Cache</strong></p><div class="example-contents"><p><span class="command"><strong>nix copy --to 's3://example-nix-cache?profile=cache-upload&scheme=https&endpoint=minio.example.com' nixpkgs.hello</strong></span></p></div></div><br class="example-break" /></div></div></div></div><div class="part"><div class="titlepage"><div><div><h1 class="title"><a id="chap-writing-nix-expressions"></a>Part IV. Writing Nix Expressions</h1></div></div></div><div class="partintro"><div></div><p>This chapter shows you how to write Nix expressions, which
|
|||
|
|
instruct Nix how to build packages. It starts with a
|
|||
|
|
simple example (a Nix expression for GNU Hello), and then moves
|
|||
|
|
on to a more in-depth look at the Nix expression language.</p><div class="note"><h3 class="title">Note</h3><p>This chapter is mostly about the Nix expression language.
|
|||
|
|
For more extensive information on adding packages to the Nix Packages
|
|||
|
|
collection (such as functions in the standard environment and coding
|
|||
|
|
conventions), please consult <a class="link" href="http://nixos.org/nixpkgs/manual/" target="_top">its
|
|||
|
|
manual</a>.</p></div></div><div class="chapter"><div class="titlepage"><div><div><h2 class="title"><a id="ch-simple-expression"></a>Chapter 14. A Simple Nix Expression</h2></div></div></div><p>This section shows how to add and test the <a class="link" href="http://www.gnu.org/software/hello/hello.html" target="_top">GNU Hello
|
|||
|
|
package</a> to the Nix Packages collection. Hello is a program
|
|||
|
|
that prints out the text <span class="quote">“<span class="quote">Hello, world!</span>”</span>.</p><p>To add a package to the Nix Packages collection, you generally
|
|||
|
|
need to do three things:
|
|||
|
|
|
|||
|
|
</p><div class="orderedlist"><ol class="orderedlist" type="1"><li class="listitem"><p>Write a Nix expression for the package. This is a
|
|||
|
|
file that describes all the inputs involved in building the package,
|
|||
|
|
such as dependencies, sources, and so on.</p></li><li class="listitem"><p>Write a <span class="emphasis"><em>builder</em></span>. This is a
|
|||
|
|
shell script<a href="#ftn.idm139733301545648" class="footnote" id="idm139733301545648"><sup class="footnote">[2]</sup></a> that actually builds the package from
|
|||
|
|
the inputs.</p></li><li class="listitem"><p>Add the package to the file
|
|||
|
|
<code class="filename">pkgs/top-level/all-packages.nix</code>. The Nix
|
|||
|
|
expression written in the first step is a
|
|||
|
|
<span class="emphasis"><em>function</em></span>; it requires other packages in order
|
|||
|
|
to build it. In this step you put it all together, i.e., you call
|
|||
|
|
the function with the right arguments to build the actual
|
|||
|
|
package.</p></li></ol></div><p>
|
|||
|
|
|
|||
|
|
</p><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a id="sec-expression-syntax"></a>14.1. Expression Syntax</h2></div></div></div><div class="example"><a id="ex-hello-nix"></a><p class="title"><strong>Example 14.1. Nix expression for GNU Hello
|
|||
|
|
(<code class="filename">default.nix</code>)</strong></p><div class="example-contents"><pre class="programlisting">
|
|||
|
|
{ stdenv, fetchurl, perl }: <a id="ex-hello-nix-co-1"></a>(1)
|
|||
|
|
|
|||
|
|
stdenv.mkDerivation { <a id="ex-hello-nix-co-2"></a>(2)
|
|||
|
|
name = "hello-2.1.1"; <a id="ex-hello-nix-co-3"></a>(3)
|
|||
|
|
builder = ./builder.sh; <a id="ex-hello-nix-co-4"></a>(4)
|
|||
|
|
src = fetchurl { <a id="ex-hello-nix-co-5"></a>(5)
|
|||
|
|
url = "ftp://ftp.nluug.nl/pub/gnu/hello/hello-2.1.1.tar.gz";
|
|||
|
|
sha256 = "1md7jsfd8pa45z73bz1kszpp01yw6x5ljkjk2hx7wl800any6465";
|
|||
|
|
};
|
|||
|
|
inherit perl; <a id="ex-hello-nix-co-6"></a>(6)
|
|||
|
|
}</pre></div></div><br class="example-break" /><p><a class="xref" href="#ex-hello-nix" title="Example 14.1. Nix expression for GNU Hello (default.nix)">Example 14.1, “Nix expression for GNU Hello
|
|||
|
|
(<code class="filename">default.nix</code>)”</a> shows a Nix expression for GNU
|
|||
|
|
Hello. It's actually already in the Nix Packages collection in
|
|||
|
|
<code class="filename">pkgs/applications/misc/hello/ex-1/default.nix</code>.
|
|||
|
|
It is customary to place each package in a separate directory and call
|
|||
|
|
the single Nix expression in that directory
|
|||
|
|
<code class="filename">default.nix</code>. The file has the following elements
|
|||
|
|
(referenced from the figure by number):
|
|||
|
|
|
|||
|
|
</p><div class="calloutlist"><table border="0" summary="Callout list"><tr><td width="5%" valign="top" align="left"><p><a href="#ex-hello-nix-co-1">(1)</a> </p></td><td valign="top" align="left"><p>This states that the expression is a
|
|||
|
|
<span class="emphasis"><em>function</em></span> that expects to be called with three
|
|||
|
|
arguments: <code class="varname">stdenv</code>, <code class="varname">fetchurl</code>,
|
|||
|
|
and <code class="varname">perl</code>. They are needed to build Hello, but
|
|||
|
|
we don't know how to build them here; that's why they are function
|
|||
|
|
arguments. <code class="varname">stdenv</code> is a package that is used
|
|||
|
|
by almost all Nix Packages packages; it provides a
|
|||
|
|
<span class="quote">“<span class="quote">standard</span>”</span> environment consisting of the things you
|
|||
|
|
would expect in a basic Unix environment: a C/C++ compiler (GCC,
|
|||
|
|
to be precise), the Bash shell, fundamental Unix tools such as
|
|||
|
|
<span class="command"><strong>cp</strong></span>, <span class="command"><strong>grep</strong></span>,
|
|||
|
|
<span class="command"><strong>tar</strong></span>, etc. <code class="varname">fetchurl</code> is a
|
|||
|
|
function that downloads files. <code class="varname">perl</code> is the
|
|||
|
|
Perl interpreter.</p><p>Nix functions generally have the form <code class="literal">{ x, y, ...,
|
|||
|
|
z }: e</code> where <code class="varname">x</code>, <code class="varname">y</code>,
|
|||
|
|
etc. are the names of the expected arguments, and where
|
|||
|
|
<em class="replaceable"><code>e</code></em> is the body of the function. So
|
|||
|
|
here, the entire remainder of the file is the body of the
|
|||
|
|
function; when given the required arguments, the body should
|
|||
|
|
describe how to build an instance of the Hello package.</p></td></tr><tr><td width="5%" valign="top" align="left"><p><a href="#ex-hello-nix-co-2">(2)</a> </p></td><td valign="top" align="left"><p>So we have to build a package. Building something from
|
|||
|
|
other stuff is called a <span class="emphasis"><em>derivation</em></span> in Nix (as
|
|||
|
|
opposed to sources, which are built by humans instead of
|
|||
|
|
computers). We perform a derivation by calling
|
|||
|
|
<code class="varname">stdenv.mkDerivation</code>.
|
|||
|
|
<code class="varname">mkDerivation</code> is a function provided by
|
|||
|
|
<code class="varname">stdenv</code> that builds a package from a set of
|
|||
|
|
<span class="emphasis"><em>attributes</em></span>. A set is just a list of
|
|||
|
|
key/value pairs where each key is a string and each value is an
|
|||
|
|
arbitrary Nix expression. They take the general form <code class="literal">{
|
|||
|
|
<em class="replaceable"><code>name1</code></em> =
|
|||
|
|
<em class="replaceable"><code>expr1</code></em>; <em class="replaceable"><code>...</code></em>
|
|||
|
|
<em class="replaceable"><code>nameN</code></em> =
|
|||
|
|
<em class="replaceable"><code>exprN</code></em>; }</code>.</p></td></tr><tr><td width="5%" valign="top" align="left"><p><a href="#ex-hello-nix-co-3">(3)</a> </p></td><td valign="top" align="left"><p>The attribute <code class="varname">name</code> specifies the symbolic
|
|||
|
|
name and version of the package. Nix doesn't really care about
|
|||
|
|
these things, but they are used by for instance <span class="command"><strong>nix-env
|
|||
|
|
-q</strong></span> to show a <span class="quote">“<span class="quote">human-readable</span>”</span> name for
|
|||
|
|
packages. This attribute is required by
|
|||
|
|
<code class="varname">mkDerivation</code>.</p></td></tr><tr><td width="5%" valign="top" align="left"><p><a href="#ex-hello-nix-co-4">(4)</a> </p></td><td valign="top" align="left"><p>The attribute <code class="varname">builder</code> specifies the
|
|||
|
|
builder. This attribute can sometimes be omitted, in which case
|
|||
|
|
<code class="varname">mkDerivation</code> will fill in a default builder
|
|||
|
|
(which does a <code class="literal">configure; make; make install</code>, in
|
|||
|
|
essence). Hello is sufficiently simple that the default builder
|
|||
|
|
would suffice, but in this case, we will show an actual builder
|
|||
|
|
for educational purposes. The value
|
|||
|
|
<span class="command"><strong>./builder.sh</strong></span> refers to the shell script shown
|
|||
|
|
in <a class="xref" href="#ex-hello-builder" title="Example 14.2. Build script for GNU Hello (builder.sh)">Example 14.2, “Build script for GNU Hello
|
|||
|
|
(<code class="filename">builder.sh</code>)”</a>, discussed below.</p></td></tr><tr><td width="5%" valign="top" align="left"><p><a href="#ex-hello-nix-co-5">(5)</a> </p></td><td valign="top" align="left"><p>The builder has to know what the sources of the package
|
|||
|
|
are. Here, the attribute <code class="varname">src</code> is bound to the
|
|||
|
|
result of a call to the <span class="command"><strong>fetchurl</strong></span> function.
|
|||
|
|
Given a URL and a SHA-256 hash of the expected contents of the file
|
|||
|
|
at that URL, this function builds a derivation that downloads the
|
|||
|
|
file and checks its hash. So the sources are a dependency that
|
|||
|
|
like all other dependencies is built before Hello itself is
|
|||
|
|
built.</p><p>Instead of <code class="varname">src</code> any other name could have
|
|||
|
|
been used, and in fact there can be any number of sources (bound
|
|||
|
|
to different attributes). However, <code class="varname">src</code> is
|
|||
|
|
customary, and it's also expected by the default builder (which we
|
|||
|
|
don't use in this example).</p></td></tr><tr><td width="5%" valign="top" align="left"><p><a href="#ex-hello-nix-co-6">(6)</a> </p></td><td valign="top" align="left"><p>Since the derivation requires Perl, we have to pass the
|
|||
|
|
value of the <code class="varname">perl</code> function argument to the
|
|||
|
|
builder. All attributes in the set are actually passed as
|
|||
|
|
environment variables to the builder, so declaring an attribute
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
perl = perl;</pre><p>
|
|||
|
|
|
|||
|
|
will do the trick: it binds an attribute <code class="varname">perl</code>
|
|||
|
|
to the function argument which also happens to be called
|
|||
|
|
<code class="varname">perl</code>. However, it looks a bit silly, so there
|
|||
|
|
is a shorter syntax. The <code class="literal">inherit</code> keyword
|
|||
|
|
causes the specified attributes to be bound to whatever variables
|
|||
|
|
with the same name happen to be in scope.</p></td></tr></table></div><p>
|
|||
|
|
|
|||
|
|
</p></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a id="sec-build-script"></a>14.2. Build Script</h2></div></div></div><div class="example"><a id="ex-hello-builder"></a><p class="title"><strong>Example 14.2. Build script for GNU Hello
|
|||
|
|
(<code class="filename">builder.sh</code>)</strong></p><div class="example-contents"><pre class="programlisting">
|
|||
|
|
source $stdenv/setup <a id="ex-hello-builder-co-1"></a>(1)
|
|||
|
|
|
|||
|
|
PATH=$perl/bin:$PATH <a id="ex-hello-builder-co-2"></a>(2)
|
|||
|
|
|
|||
|
|
tar xvfz $src <a id="ex-hello-builder-co-3"></a>(3)
|
|||
|
|
cd hello-*
|
|||
|
|
./configure --prefix=$out <a id="ex-hello-builder-co-4"></a>(4)
|
|||
|
|
make <a id="ex-hello-builder-co-5"></a>(5)
|
|||
|
|
make install</pre></div></div><br class="example-break" /><p><a class="xref" href="#ex-hello-builder" title="Example 14.2. Build script for GNU Hello (builder.sh)">Example 14.2, “Build script for GNU Hello
|
|||
|
|
(<code class="filename">builder.sh</code>)”</a> shows the builder referenced
|
|||
|
|
from Hello's Nix expression (stored in
|
|||
|
|
<code class="filename">pkgs/applications/misc/hello/ex-1/builder.sh</code>).
|
|||
|
|
The builder can actually be made a lot shorter by using the
|
|||
|
|
<span class="emphasis"><em>generic builder</em></span> functions provided by
|
|||
|
|
<code class="varname">stdenv</code>, but here we write out the build steps to
|
|||
|
|
elucidate what a builder does. It performs the following
|
|||
|
|
steps:</p><div class="calloutlist"><table border="0" summary="Callout list"><tr><td width="5%" valign="top" align="left"><p><a href="#ex-hello-builder-co-1">(1)</a> </p></td><td valign="top" align="left"><p>When Nix runs a builder, it initially completely clears the
|
|||
|
|
environment (except for the attributes declared in the
|
|||
|
|
derivation). For instance, the <code class="envar">PATH</code> variable is
|
|||
|
|
empty<a href="#ftn.idm139733301492640" class="footnote" id="idm139733301492640"><sup class="footnote">[3]</sup></a>. This is done to prevent
|
|||
|
|
undeclared inputs from being used in the build process. If for
|
|||
|
|
example the <code class="envar">PATH</code> contained
|
|||
|
|
<code class="filename">/usr/bin</code>, then you might accidentally use
|
|||
|
|
<code class="filename">/usr/bin/gcc</code>.</p><p>So the first step is to set up the environment. This is
|
|||
|
|
done by calling the <code class="filename">setup</code> script of the
|
|||
|
|
standard environment. The environment variable
|
|||
|
|
<code class="envar">stdenv</code> points to the location of the standard
|
|||
|
|
environment being used. (It wasn't specified explicitly as an
|
|||
|
|
attribute in <a class="xref" href="#ex-hello-nix" title="Example 14.1. Nix expression for GNU Hello (default.nix)">Example 14.1, “Nix expression for GNU Hello
|
|||
|
|
(<code class="filename">default.nix</code>)”</a>, but
|
|||
|
|
<code class="varname">mkDerivation</code> adds it automatically.)</p></td></tr><tr><td width="5%" valign="top" align="left"><p><a href="#ex-hello-builder-co-2">(2)</a> </p></td><td valign="top" align="left"><p>Since Hello needs Perl, we have to make sure that Perl is in
|
|||
|
|
the <code class="envar">PATH</code>. The <code class="envar">perl</code> environment
|
|||
|
|
variable points to the location of the Perl package (since it
|
|||
|
|
was passed in as an attribute to the derivation), so
|
|||
|
|
<code class="filename"><em class="replaceable"><code>$perl</code></em>/bin</code> is the
|
|||
|
|
directory containing the Perl interpreter.</p></td></tr><tr><td width="5%" valign="top" align="left"><p><a href="#ex-hello-builder-co-3">(3)</a> </p></td><td valign="top" align="left"><p>Now we have to unpack the sources. The
|
|||
|
|
<code class="varname">src</code> attribute was bound to the result of
|
|||
|
|
fetching the Hello source tarball from the network, so the
|
|||
|
|
<code class="envar">src</code> environment variable points to the location in
|
|||
|
|
the Nix store to which the tarball was downloaded. After
|
|||
|
|
unpacking, we <span class="command"><strong>cd</strong></span> to the resulting source
|
|||
|
|
directory.</p><p>The whole build is performed in a temporary directory
|
|||
|
|
created in <code class="varname">/tmp</code>, by the way. This directory is
|
|||
|
|
removed after the builder finishes, so there is no need to clean
|
|||
|
|
up the sources afterwards. Also, the temporary directory is
|
|||
|
|
always newly created, so you don't have to worry about files from
|
|||
|
|
previous builds interfering with the current build.</p></td></tr><tr><td width="5%" valign="top" align="left"><p><a href="#ex-hello-builder-co-4">(4)</a> </p></td><td valign="top" align="left"><p>GNU Hello is a typical Autoconf-based package, so we first
|
|||
|
|
have to run its <code class="filename">configure</code> script. In Nix
|
|||
|
|
every package is stored in a separate location in the Nix store,
|
|||
|
|
for instance
|
|||
|
|
<code class="filename">/nix/store/9a54ba97fb71b65fda531012d0443ce2-hello-2.1.1</code>.
|
|||
|
|
Nix computes this path by cryptographically hashing all attributes
|
|||
|
|
of the derivation. The path is passed to the builder through the
|
|||
|
|
<code class="envar">out</code> environment variable. So here we give
|
|||
|
|
<code class="filename">configure</code> the parameter
|
|||
|
|
<code class="literal">--prefix=$out</code> to cause Hello to be installed in
|
|||
|
|
the expected location.</p></td></tr><tr><td width="5%" valign="top" align="left"><p><a href="#ex-hello-builder-co-5">(5)</a> </p></td><td valign="top" align="left"><p>Finally we build Hello (<code class="literal">make</code>) and install
|
|||
|
|
it into the location specified by <code class="envar">out</code>
|
|||
|
|
(<code class="literal">make install</code>).</p></td></tr></table></div><p>If you are wondering about the absence of error checking on the
|
|||
|
|
result of various commands called in the builder: this is because the
|
|||
|
|
shell script is evaluated with Bash's <code class="option">-e</code> option,
|
|||
|
|
which causes the script to be aborted if any command fails without an
|
|||
|
|
error check.</p></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a id="sec-arguments"></a>14.3. Arguments and Variables</h2></div></div></div><div class="example"><a id="ex-hello-composition"></a><p class="title"><strong>Example 14.3. Composing GNU Hello
|
|||
|
|
(<code class="filename">all-packages.nix</code>)</strong></p><div class="example-contents"><pre class="programlisting">
|
|||
|
|
...
|
|||
|
|
|
|||
|
|
rec { <a id="ex-hello-composition-co-1"></a>(1)
|
|||
|
|
|
|||
|
|
hello = import ../applications/misc/hello/ex-1 <a id="ex-hello-composition-co-2"></a>(2) { <a id="ex-hello-composition-co-3"></a>(3)
|
|||
|
|
inherit fetchurl stdenv perl;
|
|||
|
|
};
|
|||
|
|
|
|||
|
|
perl = import ../development/interpreters/perl { <a id="ex-hello-composition-co-4"></a>(4)
|
|||
|
|
inherit fetchurl stdenv;
|
|||
|
|
};
|
|||
|
|
|
|||
|
|
fetchurl = import ../build-support/fetchurl {
|
|||
|
|
inherit stdenv; ...
|
|||
|
|
};
|
|||
|
|
|
|||
|
|
stdenv = ...;
|
|||
|
|
|
|||
|
|
}
|
|||
|
|
</pre></div></div><br class="example-break" /><p>The Nix expression in <a class="xref" href="#ex-hello-nix" title="Example 14.1. Nix expression for GNU Hello (default.nix)">Example 14.1, “Nix expression for GNU Hello
|
|||
|
|
(<code class="filename">default.nix</code>)”</a> is a
|
|||
|
|
function; it is missing some arguments that have to be filled in
|
|||
|
|
somewhere. In the Nix Packages collection this is done in the file
|
|||
|
|
<code class="filename">pkgs/top-level/all-packages.nix</code>, where all
|
|||
|
|
Nix expressions for packages are imported and called with the
|
|||
|
|
appropriate arguments. <a class="xref" href="#ex-hello-composition" title="Example 14.3. Composing GNU Hello (all-packages.nix)">Example 14.3, “Composing GNU Hello
|
|||
|
|
(<code class="filename">all-packages.nix</code>)”</a> shows
|
|||
|
|
some fragments of
|
|||
|
|
<code class="filename">all-packages.nix</code>.</p><div class="calloutlist"><table border="0" summary="Callout list"><tr><td width="5%" valign="top" align="left"><p><a href="#ex-hello-composition-co-1">(1)</a> </p></td><td valign="top" align="left"><p>This file defines a set of attributes, all of which are
|
|||
|
|
concrete derivations (i.e., not functions). In fact, we define a
|
|||
|
|
<span class="emphasis"><em>mutually recursive</em></span> set of attributes. That
|
|||
|
|
is, the attributes can refer to each other. This is precisely
|
|||
|
|
what we want since we want to <span class="quote">“<span class="quote">plug</span>”</span> the
|
|||
|
|
various packages into each other.</p></td></tr><tr><td width="5%" valign="top" align="left"><p><a href="#ex-hello-composition-co-2">(2)</a> </p></td><td valign="top" align="left"><p>Here we <span class="emphasis"><em>import</em></span> the Nix expression for
|
|||
|
|
GNU Hello. The import operation just loads and returns the
|
|||
|
|
specified Nix expression. In fact, we could just have put the
|
|||
|
|
contents of <a class="xref" href="#ex-hello-nix" title="Example 14.1. Nix expression for GNU Hello (default.nix)">Example 14.1, “Nix expression for GNU Hello
|
|||
|
|
(<code class="filename">default.nix</code>)”</a> in
|
|||
|
|
<code class="filename">all-packages.nix</code> at this point. That
|
|||
|
|
would be completely equivalent, but it would make the file rather
|
|||
|
|
bulky.</p><p>Note that we refer to
|
|||
|
|
<code class="filename">../applications/misc/hello/ex-1</code>, not
|
|||
|
|
<code class="filename">../applications/misc/hello/ex-1/default.nix</code>.
|
|||
|
|
When you try to import a directory, Nix automatically appends
|
|||
|
|
<code class="filename">/default.nix</code> to the file name.</p></td></tr><tr><td width="5%" valign="top" align="left"><p><a href="#ex-hello-composition-co-3">(3)</a> </p></td><td valign="top" align="left"><p>This is where the actual composition takes place. Here we
|
|||
|
|
<span class="emphasis"><em>call</em></span> the function imported from
|
|||
|
|
<code class="filename">../applications/misc/hello/ex-1</code> with a set
|
|||
|
|
containing the things that the function expects, namely
|
|||
|
|
<code class="varname">fetchurl</code>, <code class="varname">stdenv</code>, and
|
|||
|
|
<code class="varname">perl</code>. We use inherit again to use the
|
|||
|
|
attributes defined in the surrounding scope (we could also have
|
|||
|
|
written <code class="literal">fetchurl = fetchurl;</code>, etc.).</p><p>The result of this function call is an actual derivation
|
|||
|
|
that can be built by Nix (since when we fill in the arguments of
|
|||
|
|
the function, what we get is its body, which is the call to
|
|||
|
|
<code class="varname">stdenv.mkDerivation</code> in <a class="xref" href="#ex-hello-nix" title="Example 14.1. Nix expression for GNU Hello (default.nix)">Example 14.1, “Nix expression for GNU Hello
|
|||
|
|
(<code class="filename">default.nix</code>)”</a>).</p><div class="note"><h3 class="title">Note</h3><p>Nixpkgs has a convenience function
|
|||
|
|
<code class="function">callPackage</code> that imports and calls a
|
|||
|
|
function, filling in any missing arguments by passing the
|
|||
|
|
corresponding attribute from the Nixpkgs set, like this:
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
hello = callPackage ../applications/misc/hello/ex-1 { };
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
If necessary, you can set or override arguments:
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
hello = callPackage ../applications/misc/hello/ex-1 { stdenv = myStdenv; };
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
</p></div></td></tr><tr><td width="5%" valign="top" align="left"><p><a href="#ex-hello-composition-co-4">(4)</a> </p></td><td valign="top" align="left"><p>Likewise, we have to instantiate Perl,
|
|||
|
|
<code class="varname">fetchurl</code>, and the standard environment.</p></td></tr></table></div></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a id="sec-building-simple"></a>14.4. Building and Testing</h2></div></div></div><p>You can now try to build Hello. Of course, you could do
|
|||
|
|
<code class="literal">nix-env -i hello</code>, but you may not want to install a
|
|||
|
|
possibly broken package just yet. The best way to test the package is by
|
|||
|
|
using the command <span class="command"><strong><a class="command" href="#sec-nix-build" title="nix-build">nix-build</a></strong></span>,
|
|||
|
|
which builds a Nix expression and creates a symlink named
|
|||
|
|
<code class="filename">result</code> in the current directory:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-build -A hello
|
|||
|
|
building path `/nix/store/632d2b22514d...-hello-2.1.1'
|
|||
|
|
hello-2.1.1/
|
|||
|
|
hello-2.1.1/intl/
|
|||
|
|
hello-2.1.1/intl/ChangeLog
|
|||
|
|
<em class="replaceable"><code>...</code></em>
|
|||
|
|
|
|||
|
|
$ ls -l result
|
|||
|
|
lrwxrwxrwx ... 2006-09-29 10:43 result -> /nix/store/632d2b22514d...-hello-2.1.1
|
|||
|
|
|
|||
|
|
$ ./result/bin/hello
|
|||
|
|
Hello, world!</pre><p>
|
|||
|
|
|
|||
|
|
The <a class="link" href="#opt-attr"><code class="option">-A</code></a> option selects
|
|||
|
|
the <code class="literal">hello</code> attribute. This is faster than using the
|
|||
|
|
symbolic package name specified by the <code class="literal">name</code>
|
|||
|
|
attribute (which also happens to be <code class="literal">hello</code>) and is
|
|||
|
|
unambiguous (there can be multiple packages with the symbolic name
|
|||
|
|
<code class="literal">hello</code>, but there can be only one attribute in a set
|
|||
|
|
named <code class="literal">hello</code>).</p><p><span class="command"><strong>nix-build</strong></span> registers the
|
|||
|
|
<code class="filename">./result</code> symlink as a garbage collection root, so
|
|||
|
|
unless and until you delete the <code class="filename">./result</code> symlink,
|
|||
|
|
the output of the build will be safely kept on your system. You can
|
|||
|
|
use <span class="command"><strong>nix-build</strong></span>’s <code class="option"><a class="option" href="#opt-out-link">-o</a></code> switch to give the symlink another
|
|||
|
|
name.</p><p>Nix has transactional semantics. Once a build finishes
|
|||
|
|
successfully, Nix makes a note of this in its database: it registers
|
|||
|
|
that the path denoted by <code class="envar">out</code> is now
|
|||
|
|
<span class="quote">“<span class="quote">valid</span>”</span>. If you try to build the derivation again, Nix
|
|||
|
|
will see that the path is already valid and finish immediately. If a
|
|||
|
|
build fails, either because it returns a non-zero exit code, because
|
|||
|
|
Nix or the builder are killed, or because the machine crashes, then
|
|||
|
|
the output paths will not be registered as valid. If you try to build
|
|||
|
|
the derivation again, Nix will remove the output paths if they exist
|
|||
|
|
(e.g., because the builder died half-way through <code class="literal">make
|
|||
|
|
install</code>) and try again. Note that there is no
|
|||
|
|
<span class="quote">“<span class="quote">negative caching</span>”</span>: Nix doesn't remember that a build
|
|||
|
|
failed, and so a failed build can always be repeated. This is because
|
|||
|
|
Nix cannot distinguish between permanent failures (e.g., a compiler
|
|||
|
|
error due to a syntax error in the source) and transient failures
|
|||
|
|
(e.g., a disk full condition).</p><p>Nix also performs locking. If you run multiple Nix builds
|
|||
|
|
simultaneously, and they try to build the same derivation, the first
|
|||
|
|
Nix instance that gets there will perform the build, while the others
|
|||
|
|
block (or perform other derivations if available) until the build
|
|||
|
|
finishes:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-build -A hello
|
|||
|
|
waiting for lock on `/nix/store/0h5b7hp8d4hqfrw8igvx97x1xawrjnac-hello-2.1.1x'</pre><p>
|
|||
|
|
|
|||
|
|
So it is always safe to run multiple instances of Nix in parallel
|
|||
|
|
(which isn’t the case with, say, <span class="command"><strong>make</strong></span>).</p></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a id="sec-generic-builder"></a>14.5. Generic Builder Syntax</h2></div></div></div><p>Recall from <a class="xref" href="#ex-hello-builder" title="Example 14.2. Build script for GNU Hello (builder.sh)">Example 14.2, “Build script for GNU Hello
|
|||
|
|
(<code class="filename">builder.sh</code>)”</a> that the builder
|
|||
|
|
looked something like this:
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
PATH=$perl/bin:$PATH
|
|||
|
|
tar xvfz $src
|
|||
|
|
cd hello-*
|
|||
|
|
./configure --prefix=$out
|
|||
|
|
make
|
|||
|
|
make install</pre><p>
|
|||
|
|
|
|||
|
|
The builders for almost all Unix packages look like this — set up some
|
|||
|
|
environment variables, unpack the sources, configure, build, and
|
|||
|
|
install. For this reason the standard environment provides some Bash
|
|||
|
|
functions that automate the build process. A builder using the
|
|||
|
|
generic build facilities in shown in <a class="xref" href="#ex-hello-builder2" title="Example 14.4. Build script using the generic build functions">Example 14.4, “Build script using the generic
|
|||
|
|
build functions”</a>.</p><div class="example"><a id="ex-hello-builder2"></a><p class="title"><strong>Example 14.4. Build script using the generic
|
|||
|
|
build functions</strong></p><div class="example-contents"><pre class="programlisting">
|
|||
|
|
buildInputs="$perl" <a id="ex-hello-builder2-co-1"></a>(1)
|
|||
|
|
|
|||
|
|
source $stdenv/setup <a id="ex-hello-builder2-co-2"></a>(2)
|
|||
|
|
|
|||
|
|
genericBuild <a id="ex-hello-builder2-co-3"></a>(3)</pre></div></div><br class="example-break" /><div class="calloutlist"><table border="0" summary="Callout list"><tr><td width="5%" valign="top" align="left"><p><a href="#ex-hello-builder2-co-1">(1)</a> </p></td><td valign="top" align="left"><p>The <code class="envar">buildInputs</code> variable tells
|
|||
|
|
<code class="filename">setup</code> to use the indicated packages as
|
|||
|
|
<span class="quote">“<span class="quote">inputs</span>”</span>. This means that if a package provides a
|
|||
|
|
<code class="filename">bin</code> subdirectory, it's added to
|
|||
|
|
<code class="envar">PATH</code>; if it has a <code class="filename">include</code>
|
|||
|
|
subdirectory, it's added to GCC's header search path; and so
|
|||
|
|
on.<a href="#ftn.idm139733301420112" class="footnote" id="idm139733301420112"><sup class="footnote">[4]</sup></a>
|
|||
|
|
</p></td></tr><tr><td width="5%" valign="top" align="left"><p><a href="#ex-hello-builder2-co-2">(2)</a> </p></td><td valign="top" align="left"><p>The function <code class="function">genericBuild</code> is defined in
|
|||
|
|
the file <code class="literal">$stdenv/setup</code>.</p></td></tr><tr><td width="5%" valign="top" align="left"><p><a href="#ex-hello-builder2-co-3">(3)</a> </p></td><td valign="top" align="left"><p>The final step calls the shell function
|
|||
|
|
<code class="function">genericBuild</code>, which performs the steps that
|
|||
|
|
were done explicitly in <a class="xref" href="#ex-hello-builder" title="Example 14.2. Build script for GNU Hello (builder.sh)">Example 14.2, “Build script for GNU Hello
|
|||
|
|
(<code class="filename">builder.sh</code>)”</a>. The
|
|||
|
|
generic builder is smart enough to figure out whether to unpack
|
|||
|
|
the sources using <span class="command"><strong>gzip</strong></span>,
|
|||
|
|
<span class="command"><strong>bzip2</strong></span>, etc. It can be customised in many ways;
|
|||
|
|
see the Nixpkgs manual for details.</p></td></tr></table></div><p>Discerning readers will note that the
|
|||
|
|
<code class="envar">buildInputs</code> could just as well have been set in the Nix
|
|||
|
|
expression, like this:
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
buildInputs = [ perl ];</pre><p>
|
|||
|
|
|
|||
|
|
The <code class="varname">perl</code> attribute can then be removed, and the
|
|||
|
|
builder becomes even shorter:
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
source $stdenv/setup
|
|||
|
|
genericBuild</pre><p>
|
|||
|
|
|
|||
|
|
In fact, <code class="varname">mkDerivation</code> provides a default builder
|
|||
|
|
that looks exactly like that, so it is actually possible to omit the
|
|||
|
|
builder for Hello entirely.</p></div><div class="footnotes"><br /><hr style="width:100; text-align:left;margin-left: 0" /><div id="ftn.idm139733301545648" class="footnote"><p><a href="#idm139733301545648" class="para"><sup class="para">[2] </sup></a>In fact, it can be written in any
|
|||
|
|
language, but typically it's a <span class="command"><strong>bash</strong></span> shell
|
|||
|
|
script.</p></div><div id="ftn.idm139733301492640" class="footnote"><p><a href="#idm139733301492640" class="para"><sup class="para">[3] </sup></a>Actually, it's initialised to
|
|||
|
|
<code class="filename">/path-not-set</code> to prevent Bash from setting it
|
|||
|
|
to a default value.</p></div><div id="ftn.idm139733301420112" class="footnote"><p><a href="#idm139733301420112" class="para"><sup class="para">[4] </sup></a>How does it work? <code class="filename">setup</code>
|
|||
|
|
tries to source the file
|
|||
|
|
<code class="filename"><em class="replaceable"><code>pkg</code></em>/nix-support/setup-hook</code>
|
|||
|
|
of all dependencies. These “setup hooks” can then set up whatever
|
|||
|
|
environment variables they want; for instance, the setup hook for
|
|||
|
|
Perl sets the <code class="envar">PERL5LIB</code> environment variable to
|
|||
|
|
contain the <code class="filename">lib/site_perl</code> directories of all
|
|||
|
|
inputs.</p></div></div></div><div class="chapter"><div class="titlepage"><div><div><h2 class="title"><a id="ch-expression-language"></a>Chapter 15. Nix Expression Language</h2></div></div></div><p>The Nix expression language is a pure, lazy, functional
|
|||
|
|
language. Purity means that operations in the language don't have
|
|||
|
|
side-effects (for instance, there is no variable assignment).
|
|||
|
|
Laziness means that arguments to functions are evaluated only when
|
|||
|
|
they are needed. Functional means that functions are
|
|||
|
|
<span class="quote">“<span class="quote">normal</span>”</span> values that can be passed around and manipulated
|
|||
|
|
in interesting ways. The language is not a full-featured, general
|
|||
|
|
purpose language. Its main job is to describe packages,
|
|||
|
|
compositions of packages, and the variability within
|
|||
|
|
packages.</p><p>This section presents the various features of the
|
|||
|
|
language.</p><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a id="ssec-values"></a>15.1. Values</h2></div></div></div><div class="simplesect"><div class="titlepage"><div><div><h3 class="title"><a id="idm139733301403360"></a>Simple Values</h3></div></div></div><p>Nix has the following basic data types:
|
|||
|
|
|
|||
|
|
</p><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><p><span class="emphasis"><em>Strings</em></span> can be written in three
|
|||
|
|
ways.</p><p>The most common way is to enclose the string between double
|
|||
|
|
quotes, e.g., <code class="literal">"foo bar"</code>. Strings can span
|
|||
|
|
multiple lines. The special characters <code class="literal">"</code> and
|
|||
|
|
<code class="literal">\</code> and the character sequence
|
|||
|
|
<code class="literal">${</code> must be escaped by prefixing them with a
|
|||
|
|
backslash (<code class="literal">\</code>). Newlines, carriage returns and
|
|||
|
|
tabs can be written as <code class="literal">\n</code>,
|
|||
|
|
<code class="literal">\r</code> and <code class="literal">\t</code>,
|
|||
|
|
respectively.</p><p>You can include the result of an expression into a string by
|
|||
|
|
enclosing it in
|
|||
|
|
<code class="literal">${<em class="replaceable"><code>...</code></em>}</code>, a feature
|
|||
|
|
known as <span class="emphasis"><em>antiquotation</em></span>. The enclosed
|
|||
|
|
expression must evaluate to something that can be coerced into a
|
|||
|
|
string (meaning that it must be a string, a path, or a
|
|||
|
|
derivation). For instance, rather than writing
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
"--with-freetype2-library=" + freetype + "/lib"</pre><p>
|
|||
|
|
|
|||
|
|
(where <code class="varname">freetype</code> is a derivation), you can
|
|||
|
|
instead write the more natural
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
"--with-freetype2-library=${freetype}/lib"</pre><p>
|
|||
|
|
|
|||
|
|
The latter is automatically translated to the former. A more
|
|||
|
|
complicated example (from the Nix expression for <a class="link" href="http://www.trolltech.com/products/qt" target="_top">Qt</a>):
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
configureFlags = "
|
|||
|
|
-system-zlib -system-libpng -system-libjpeg
|
|||
|
|
${if openglSupport then "-dlopen-opengl
|
|||
|
|
-L${mesa}/lib -I${mesa}/include
|
|||
|
|
-L${libXmu}/lib -I${libXmu}/include" else ""}
|
|||
|
|
${if threadSupport then "-thread" else "-no-thread"}
|
|||
|
|
";</pre><p>
|
|||
|
|
|
|||
|
|
Note that Nix expressions and strings can be arbitrarily nested;
|
|||
|
|
in this case the outer string contains various antiquotations that
|
|||
|
|
themselves contain strings (e.g., <code class="literal">"-thread"</code>),
|
|||
|
|
some of which in turn contain expressions (e.g.,
|
|||
|
|
<code class="literal">${mesa}</code>).</p><p>The second way to write string literals is as an
|
|||
|
|
<span class="emphasis"><em>indented string</em></span>, which is enclosed between
|
|||
|
|
pairs of <span class="emphasis"><em>double single-quotes</em></span>, like so:
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
''
|
|||
|
|
This is the first line.
|
|||
|
|
This is the second line.
|
|||
|
|
This is the third line.
|
|||
|
|
''</pre><p>
|
|||
|
|
|
|||
|
|
This kind of string literal intelligently strips indentation from
|
|||
|
|
the start of each line. To be precise, it strips from each line a
|
|||
|
|
number of spaces equal to the minimal indentation of the string as
|
|||
|
|
a whole (disregarding the indentation of empty lines). For
|
|||
|
|
instance, the first and second line are indented two space, while
|
|||
|
|
the third line is indented four spaces. Thus, two spaces are
|
|||
|
|
stripped from each line, so the resulting string is
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
"This is the first line.\nThis is the second line.\n This is the third line.\n"</pre><p>
|
|||
|
|
|
|||
|
|
</p><p>Note that the whitespace and newline following the opening
|
|||
|
|
<code class="literal">''</code> is ignored if there is no non-whitespace
|
|||
|
|
text on the initial line.</p><p>Antiquotation
|
|||
|
|
(<code class="literal">${<em class="replaceable"><code>expr</code></em>}</code>) is
|
|||
|
|
supported in indented strings.</p><p>Since <code class="literal">${</code> and <code class="literal">''</code> have
|
|||
|
|
special meaning in indented strings, you need a way to quote them.
|
|||
|
|
<code class="literal">$</code> can be escaped by prefixing it with
|
|||
|
|
<code class="literal">''</code> (that is, two single quotes), i.e.,
|
|||
|
|
<code class="literal">''$</code>. <code class="literal">''</code> can be escaped by
|
|||
|
|
prefixing it with <code class="literal">'</code>, i.e.,
|
|||
|
|
<code class="literal">'''</code>. <code class="literal">$</code> removes any special meaning
|
|||
|
|
from the following <code class="literal">$</code>. Linefeed, carriage-return and tab
|
|||
|
|
characters can be written as <code class="literal">''\n</code>,
|
|||
|
|
<code class="literal">''\r</code>, <code class="literal">''\t</code>, and <code class="literal">''\</code>
|
|||
|
|
escapes any other character.
|
|||
|
|
|
|||
|
|
</p><p>Indented strings are primarily useful in that they allow
|
|||
|
|
multi-line string literals to follow the indentation of the
|
|||
|
|
enclosing Nix expression, and that less escaping is typically
|
|||
|
|
necessary for strings representing languages such as shell scripts
|
|||
|
|
and configuration files because <code class="literal">''</code> is much less
|
|||
|
|
common than <code class="literal">"</code>. Example:
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
stdenv.mkDerivation {
|
|||
|
|
<em class="replaceable"><code>...</code></em>
|
|||
|
|
postInstall =
|
|||
|
|
''
|
|||
|
|
mkdir $out/bin $out/etc
|
|||
|
|
cp foo $out/bin
|
|||
|
|
echo "Hello World" > $out/etc/foo.conf
|
|||
|
|
${if enableBar then "cp bar $out/bin" else ""}
|
|||
|
|
'';
|
|||
|
|
<em class="replaceable"><code>...</code></em>
|
|||
|
|
}
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
</p><p>Finally, as a convenience, <span class="emphasis"><em>URIs</em></span> as
|
|||
|
|
defined in appendix B of <a class="link" href="http://www.ietf.org/rfc/rfc2396.txt" target="_top">RFC 2396</a>
|
|||
|
|
can be written <span class="emphasis"><em>as is</em></span>, without quotes. For
|
|||
|
|
instance, the string
|
|||
|
|
<code class="literal">"http://example.org/foo.tar.bz2"</code>
|
|||
|
|
can also be written as
|
|||
|
|
<code class="literal">http://example.org/foo.tar.bz2</code>.</p></li><li class="listitem"><p>Numbers, which can be <span class="emphasis"><em>integers</em></span> (like
|
|||
|
|
<code class="literal">123</code>) or <span class="emphasis"><em>floating point</em></span> (like
|
|||
|
|
<code class="literal">123.43</code> or <code class="literal">.27e13</code>).</p><p>Numbers are type-compatible: pure integer operations will always
|
|||
|
|
return integers, whereas any operation involving at least one floating point
|
|||
|
|
number will have a floating point number as a result.</p></li><li class="listitem"><p><span class="emphasis"><em>Paths</em></span>, e.g.,
|
|||
|
|
<code class="filename">/bin/sh</code> or <code class="filename">./builder.sh</code>.
|
|||
|
|
A path must contain at least one slash to be recognised as such; for
|
|||
|
|
instance, <code class="filename">builder.sh</code> is not a
|
|||
|
|
path<a href="#ftn.idm139733301368560" class="footnote" id="idm139733301368560"><sup class="footnote">[5]</sup></a>. If the file name is
|
|||
|
|
relative, i.e., if it does not begin with a slash, it is made
|
|||
|
|
absolute at parse time relative to the directory of the Nix
|
|||
|
|
expression that contained it. For instance, if a Nix expression in
|
|||
|
|
<code class="filename">/foo/bar/bla.nix</code> refers to
|
|||
|
|
<code class="filename">../xyzzy/fnord.nix</code>, the absolute path is
|
|||
|
|
<code class="filename">/foo/xyzzy/fnord.nix</code>.</p><p>If the first component of a path is a <code class="literal">~</code>,
|
|||
|
|
it is interpreted as if the rest of the path were relative to the
|
|||
|
|
user's home directory. e.g. <code class="filename">~/foo</code> would be
|
|||
|
|
equivalent to <code class="filename">/home/edolstra/foo</code> for a user
|
|||
|
|
whose home directory is <code class="filename">/home/edolstra</code>.
|
|||
|
|
</p><p>Paths can also be specified between angle brackets, e.g.
|
|||
|
|
<code class="literal"><nixpkgs></code>. This means that the directories
|
|||
|
|
listed in the environment variable
|
|||
|
|
<code class="envar"><a class="envar" href="#env-NIX_PATH">NIX_PATH</a></code> will be searched
|
|||
|
|
for the given file or directory name.
|
|||
|
|
</p></li><li class="listitem"><p><span class="emphasis"><em>Booleans</em></span> with values
|
|||
|
|
<code class="literal">true</code> and
|
|||
|
|
<code class="literal">false</code>.</p></li><li class="listitem"><p>The null value, denoted as
|
|||
|
|
<code class="literal">null</code>.</p></li></ul></div><p>
|
|||
|
|
|
|||
|
|
</p></div><div class="simplesect"><div class="titlepage"><div><div><h3 class="title"><a id="idm139733301358208"></a>Lists</h3></div></div></div><p>Lists are formed by enclosing a whitespace-separated list of
|
|||
|
|
values between square brackets. For example,
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
[ 123 ./foo.nix "abc" (f { x = y; }) ]</pre><p>
|
|||
|
|
|
|||
|
|
defines a list of four elements, the last being the result of a call
|
|||
|
|
to the function <code class="varname">f</code>. Note that function calls have
|
|||
|
|
to be enclosed in parentheses. If they had been omitted, e.g.,
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
[ 123 ./foo.nix "abc" f { x = y; } ]</pre><p>
|
|||
|
|
|
|||
|
|
the result would be a list of five elements, the fourth one being a
|
|||
|
|
function and the fifth being a set.</p><p>Note that lists are only lazy in values, and they are strict in length.
|
|||
|
|
</p></div><div class="simplesect"><div class="titlepage"><div><div><h3 class="title"><a id="idm139733301354960"></a>Sets</h3></div></div></div><p>Sets are really the core of the language, since ultimately the
|
|||
|
|
Nix language is all about creating derivations, which are really just
|
|||
|
|
sets of attributes to be passed to build scripts.</p><p>Sets are just a list of name/value pairs (called
|
|||
|
|
<span class="emphasis"><em>attributes</em></span>) enclosed in curly brackets, where
|
|||
|
|
each value is an arbitrary expression terminated by a semicolon. For
|
|||
|
|
example:
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
{ x = 123;
|
|||
|
|
text = "Hello";
|
|||
|
|
y = f { bla = 456; };
|
|||
|
|
}</pre><p>
|
|||
|
|
|
|||
|
|
This defines a set with attributes named <code class="varname">x</code>,
|
|||
|
|
<code class="varname">text</code>, <code class="varname">y</code>. The order of the
|
|||
|
|
attributes is irrelevant. An attribute name may only occur
|
|||
|
|
once.</p><p>Attributes can be selected from a set using the
|
|||
|
|
<code class="literal">.</code> operator. For instance,
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
{ a = "Foo"; b = "Bar"; }.a</pre><p>
|
|||
|
|
|
|||
|
|
evaluates to <code class="literal">"Foo"</code>. It is possible to provide a
|
|||
|
|
default value in an attribute selection using the
|
|||
|
|
<code class="literal">or</code> keyword. For example,
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
{ a = "Foo"; b = "Bar"; }.c or "Xyzzy"</pre><p>
|
|||
|
|
|
|||
|
|
will evaluate to <code class="literal">"Xyzzy"</code> because there is no
|
|||
|
|
<code class="varname">c</code> attribute in the set.</p><p>You can use arbitrary double-quoted strings as attribute
|
|||
|
|
names:
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
{ "foo ${bar}" = 123; "nix-1.0" = 456; }."foo ${bar}"
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
This will evaluate to <code class="literal">123</code> (Assuming
|
|||
|
|
<code class="literal">bar</code> is antiquotable). In the case where an
|
|||
|
|
attribute name is just a single antiquotation, the quotes can be
|
|||
|
|
dropped:
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
{ foo = 123; }.${bar} or 456 </pre><p>
|
|||
|
|
|
|||
|
|
This will evaluate to <code class="literal">123</code> if
|
|||
|
|
<code class="literal">bar</code> evaluates to <code class="literal">"foo"</code> when
|
|||
|
|
coerced to a string and <code class="literal">456</code> otherwise (again
|
|||
|
|
assuming <code class="literal">bar</code> is antiquotable).</p><p>In the special case where an attribute name inside of a set declaration
|
|||
|
|
evaluates to <code class="literal">null</code> (which is normally an error, as
|
|||
|
|
<code class="literal">null</code> is not antiquotable), that attribute is simply not
|
|||
|
|
added to the set:
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
{ ${if foo then "bar" else null} = true; }</pre><p>
|
|||
|
|
|
|||
|
|
This will evaluate to <code class="literal">{}</code> if <code class="literal">foo</code>
|
|||
|
|
evaluates to <code class="literal">false</code>.</p><p>A set that has a <code class="literal">__functor</code> attribute whose value
|
|||
|
|
is callable (i.e. is itself a function or a set with a
|
|||
|
|
<code class="literal">__functor</code> attribute whose value is callable) can be
|
|||
|
|
applied as if it were a function, with the set itself passed in first
|
|||
|
|
, e.g.,
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
let add = { __functor = self: x: x + self.x; };
|
|||
|
|
inc = add // { x = 1; };
|
|||
|
|
in inc 1
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
evaluates to <code class="literal">2</code>. This can be used to attach metadata to a
|
|||
|
|
function without the caller needing to treat it specially, or to implement
|
|||
|
|
a form of object-oriented programming, for example.
|
|||
|
|
|
|||
|
|
</p></div></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a id="sec-constructs"></a>15.2. Language Constructs</h2></div></div></div><div class="simplesect"><div class="titlepage"><div><div><h3 class="title"><a id="idm139733301335376"></a>Recursive sets</h3></div></div></div><p>Recursive sets are just normal sets, but the attributes can
|
|||
|
|
refer to each other. For example,
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
rec {
|
|||
|
|
x = y;
|
|||
|
|
y = 123;
|
|||
|
|
}.x
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
evaluates to <code class="literal">123</code>. Note that without
|
|||
|
|
<code class="literal">rec</code> the binding <code class="literal">x = y;</code> would
|
|||
|
|
refer to the variable <code class="varname">y</code> in the surrounding scope,
|
|||
|
|
if one exists, and would be invalid if no such variable exists. That
|
|||
|
|
is, in a normal (non-recursive) set, attributes are not added to the
|
|||
|
|
lexical scope; in a recursive set, they are.</p><p>Recursive sets of course introduce the danger of infinite
|
|||
|
|
recursion. For example,
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
rec {
|
|||
|
|
x = y;
|
|||
|
|
y = x;
|
|||
|
|
}.x</pre><p>
|
|||
|
|
|
|||
|
|
does not terminate<a href="#ftn.idm139733301331328" class="footnote" id="idm139733301331328"><sup class="footnote">[6]</sup></a>.</p></div><div class="simplesect"><div class="titlepage"><div><div><h3 class="title"><a id="sect-let-expressions"></a>Let-expressions</h3></div></div></div><p>A let-expression allows you to define local variables for an
|
|||
|
|
expression. For instance,
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
let
|
|||
|
|
x = "foo";
|
|||
|
|
y = "bar";
|
|||
|
|
in x + y</pre><p>
|
|||
|
|
|
|||
|
|
evaluates to <code class="literal">"foobar"</code>.
|
|||
|
|
|
|||
|
|
</p></div><div class="simplesect"><div class="titlepage"><div><div><h3 class="title"><a id="idm139733301327568"></a>Inheriting attributes</h3></div></div></div><p>When defining a set or in a let-expression it is often convenient to copy variables
|
|||
|
|
from the surrounding lexical scope (e.g., when you want to propagate
|
|||
|
|
attributes). This can be shortened using the
|
|||
|
|
<code class="literal">inherit</code> keyword. For instance,
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
let x = 123; in
|
|||
|
|
{ inherit x;
|
|||
|
|
y = 456;
|
|||
|
|
}</pre><p>
|
|||
|
|
|
|||
|
|
is equivalent to
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
let x = 123; in
|
|||
|
|
{ x = x;
|
|||
|
|
y = 456;
|
|||
|
|
}</pre><p>
|
|||
|
|
|
|||
|
|
and both evaluate to <code class="literal">{ x = 123; y = 456; }</code>. (Note that
|
|||
|
|
this works because <code class="varname">x</code> is added to the lexical scope
|
|||
|
|
by the <code class="literal">let</code> construct.) It is also possible to
|
|||
|
|
inherit attributes from another set. For instance, in this fragment
|
|||
|
|
from <code class="filename">all-packages.nix</code>,
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
graphviz = (import ../tools/graphics/graphviz) {
|
|||
|
|
inherit fetchurl stdenv libpng libjpeg expat x11 yacc;
|
|||
|
|
inherit (xlibs) libXaw;
|
|||
|
|
};
|
|||
|
|
|
|||
|
|
xlibs = {
|
|||
|
|
libX11 = ...;
|
|||
|
|
libXaw = ...;
|
|||
|
|
...
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
libpng = ...;
|
|||
|
|
libjpg = ...;
|
|||
|
|
...</pre><p>
|
|||
|
|
|
|||
|
|
the set used in the function call to the function defined in
|
|||
|
|
<code class="filename">../tools/graphics/graphviz</code> inherits a number of
|
|||
|
|
variables from the surrounding scope (<code class="varname">fetchurl</code>
|
|||
|
|
... <code class="varname">yacc</code>), but also inherits
|
|||
|
|
<code class="varname">libXaw</code> (the X Athena Widgets) from the
|
|||
|
|
<code class="varname">xlibs</code> (X11 client-side libraries) set.</p><p>
|
|||
|
|
Summarizing the fragment
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
...
|
|||
|
|
inherit x y z;
|
|||
|
|
inherit (src-set) a b c;
|
|||
|
|
...</pre><p>
|
|||
|
|
|
|||
|
|
is equivalent to
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
...
|
|||
|
|
x = x; y = y; z = z;
|
|||
|
|
a = src-set.a; b = src-set.b; c = src-set.c;
|
|||
|
|
...</pre><p>
|
|||
|
|
|
|||
|
|
when used while defining local variables in a let-expression or
|
|||
|
|
while defining a set.</p></div><div class="simplesect"><div class="titlepage"><div><div><h3 class="title"><a id="ss-functions"></a>Functions</h3></div></div></div><p>Functions have the following form:
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
<em class="replaceable"><code>pattern</code></em>: <em class="replaceable"><code>body</code></em></pre><p>
|
|||
|
|
|
|||
|
|
The pattern specifies what the argument of the function must look
|
|||
|
|
like, and binds variables in the body to (parts of) the
|
|||
|
|
argument. There are three kinds of patterns:</p><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><p>If a pattern is a single identifier, then the
|
|||
|
|
function matches any argument. Example:
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
let negate = x: !x;
|
|||
|
|
concat = x: y: x + y;
|
|||
|
|
in if negate true then concat "foo" "bar" else ""</pre><p>
|
|||
|
|
|
|||
|
|
Note that <code class="function">concat</code> is a function that takes one
|
|||
|
|
argument and returns a function that takes another argument. This
|
|||
|
|
allows partial parameterisation (i.e., only filling some of the
|
|||
|
|
arguments of a function); e.g.,
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
map (concat "foo") [ "bar" "bla" "abc" ]</pre><p>
|
|||
|
|
|
|||
|
|
evaluates to <code class="literal">[ "foobar" "foobla"
|
|||
|
|
"fooabc" ]</code>.</p></li><li class="listitem"><p>A <span class="emphasis"><em>set pattern</em></span> of the form
|
|||
|
|
<code class="literal">{ name1, name2, …, nameN }</code> matches a set
|
|||
|
|
containing the listed attributes, and binds the values of those
|
|||
|
|
attributes to variables in the function body. For example, the
|
|||
|
|
function
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
{ x, y, z }: z + y + x</pre><p>
|
|||
|
|
|
|||
|
|
can only be called with a set containing exactly the attributes
|
|||
|
|
<code class="varname">x</code>, <code class="varname">y</code> and
|
|||
|
|
<code class="varname">z</code>. No other attributes are allowed. If you want
|
|||
|
|
to allow additional arguments, you can use an ellipsis
|
|||
|
|
(<code class="literal">...</code>):
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
{ x, y, z, ... }: z + y + x</pre><p>
|
|||
|
|
|
|||
|
|
This works on any set that contains at least the three named
|
|||
|
|
attributes.</p><p>It is possible to provide <span class="emphasis"><em>default values</em></span>
|
|||
|
|
for attributes, in which case they are allowed to be missing. A
|
|||
|
|
default value is specified by writing
|
|||
|
|
<code class="literal"><em class="replaceable"><code>name</code></em> ?
|
|||
|
|
<em class="replaceable"><code>e</code></em></code>, where
|
|||
|
|
<em class="replaceable"><code>e</code></em> is an arbitrary expression. For example,
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
{ x, y ? "foo", z ? "bar" }: z + y + x</pre><p>
|
|||
|
|
|
|||
|
|
specifies a function that only requires an attribute named
|
|||
|
|
<code class="varname">x</code>, but optionally accepts <code class="varname">y</code>
|
|||
|
|
and <code class="varname">z</code>.</p></li><li class="listitem"><p>An <code class="literal">@</code>-pattern provides a means of referring
|
|||
|
|
to the whole value being matched:
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting"> args@{ x, y, z, ... }: z + y + x + args.a</pre><p>
|
|||
|
|
|
|||
|
|
but can also be written as:
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting"> { x, y, z, ... } @ args: z + y + x + args.a</pre><p>
|
|||
|
|
|
|||
|
|
Here <code class="varname">args</code> is bound to the entire argument, which
|
|||
|
|
is further matched against the pattern <code class="literal">{ x, y, z,
|
|||
|
|
... }</code>. <code class="literal">@</code>-pattern makes mainly sense with an
|
|||
|
|
ellipsis(<code class="literal">...</code>) as you can access attribute names as
|
|||
|
|
<code class="literal">a</code>, using <code class="literal">args.a</code>, which was given as an
|
|||
|
|
additional attribute to the function.
|
|||
|
|
</p><div class="warning"><h3 class="title">Warning</h3><p>
|
|||
|
|
The <code class="literal">args@</code> expression is bound to the argument passed to the function which
|
|||
|
|
means that attributes with defaults that aren't explicitly specified in the function call
|
|||
|
|
won't cause an evaluation error, but won't exist in <code class="literal">args</code>.
|
|||
|
|
</p><p>
|
|||
|
|
For instance
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
let
|
|||
|
|
function = args@{ a ? 23, ... }: args;
|
|||
|
|
in
|
|||
|
|
function {}
|
|||
|
|
</pre><p>
|
|||
|
|
will evaluate to an empty attribute set.
|
|||
|
|
</p></div></li></ul></div><p>Note that functions do not have names. If you want to give them
|
|||
|
|
a name, you can bind them to an attribute, e.g.,
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
let concat = { x, y }: x + y;
|
|||
|
|
in concat { x = "foo"; y = "bar"; }</pre><p>
|
|||
|
|
|
|||
|
|
</p></div><div class="simplesect"><div class="titlepage"><div><div><h3 class="title"><a id="idm139733301295536"></a>Conditionals</h3></div></div></div><p>Conditionals look like this:
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
if <em class="replaceable"><code>e1</code></em> then <em class="replaceable"><code>e2</code></em> else <em class="replaceable"><code>e3</code></em></pre><p>
|
|||
|
|
|
|||
|
|
where <em class="replaceable"><code>e1</code></em> is an expression that should
|
|||
|
|
evaluate to a Boolean value (<code class="literal">true</code> or
|
|||
|
|
<code class="literal">false</code>).</p></div><div class="simplesect"><div class="titlepage"><div><div><h3 class="title"><a id="idm139733301291568"></a>Assertions</h3></div></div></div><p>Assertions are generally used to check that certain requirements
|
|||
|
|
on or between features and dependencies hold. They look like this:
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
assert <em class="replaceable"><code>e1</code></em>; <em class="replaceable"><code>e2</code></em></pre><p>
|
|||
|
|
|
|||
|
|
where <em class="replaceable"><code>e1</code></em> is an expression that should
|
|||
|
|
evaluate to a Boolean value. If it evaluates to
|
|||
|
|
<code class="literal">true</code>, <em class="replaceable"><code>e2</code></em> is returned;
|
|||
|
|
otherwise expression evaluation is aborted and a backtrace is printed.</p><div class="example"><a id="ex-subversion-nix"></a><p class="title"><strong>Example 15.1. Nix expression for Subversion</strong></p><div class="example-contents"><pre class="programlisting">
|
|||
|
|
{ localServer ? false
|
|||
|
|
, httpServer ? false
|
|||
|
|
, sslSupport ? false
|
|||
|
|
, pythonBindings ? false
|
|||
|
|
, javaSwigBindings ? false
|
|||
|
|
, javahlBindings ? false
|
|||
|
|
, stdenv, fetchurl
|
|||
|
|
, openssl ? null, httpd ? null, db4 ? null, expat, swig ? null, j2sdk ? null
|
|||
|
|
}:
|
|||
|
|
|
|||
|
|
assert localServer -> db4 != null; <a id="ex-subversion-nix-co-1"></a>(1)
|
|||
|
|
assert httpServer -> httpd != null && httpd.expat == expat; <a id="ex-subversion-nix-co-2"></a>(2)
|
|||
|
|
assert sslSupport -> openssl != null && (httpServer -> httpd.openssl == openssl); <a id="ex-subversion-nix-co-3"></a>(3)
|
|||
|
|
assert pythonBindings -> swig != null && swig.pythonSupport;
|
|||
|
|
assert javaSwigBindings -> swig != null && swig.javaSupport;
|
|||
|
|
assert javahlBindings -> j2sdk != null;
|
|||
|
|
|
|||
|
|
stdenv.mkDerivation {
|
|||
|
|
name = "subversion-1.1.1";
|
|||
|
|
...
|
|||
|
|
openssl = if sslSupport then openssl else null; <a id="ex-subversion-nix-co-4"></a>(4)
|
|||
|
|
...
|
|||
|
|
}</pre></div></div><br class="example-break" /><p><a class="xref" href="#ex-subversion-nix" title="Example 15.1. Nix expression for Subversion">Example 15.1, “Nix expression for Subversion”</a> show how assertions are
|
|||
|
|
used in the Nix expression for Subversion.</p><div class="calloutlist"><table border="0" summary="Callout list"><tr><td width="5%" valign="top" align="left"><p><a href="#ex-subversion-nix-co-1">(1)</a> </p></td><td valign="top" align="left"><p>This assertion states that if Subversion is to have support
|
|||
|
|
for local repositories, then Berkeley DB is needed. So if the
|
|||
|
|
Subversion function is called with the
|
|||
|
|
<code class="varname">localServer</code> argument set to
|
|||
|
|
<code class="literal">true</code> but the <code class="varname">db4</code> argument
|
|||
|
|
set to <code class="literal">null</code>, then the evaluation fails.</p></td></tr><tr><td width="5%" valign="top" align="left"><p><a href="#ex-subversion-nix-co-2">(2)</a> </p></td><td valign="top" align="left"><p>This is a more subtle condition: if Subversion is built with
|
|||
|
|
Apache (<code class="literal">httpServer</code>) support, then the Expat
|
|||
|
|
library (an XML library) used by Subversion should be same as the
|
|||
|
|
one used by Apache. This is because in this configuration
|
|||
|
|
Subversion code ends up being linked with Apache code, and if the
|
|||
|
|
Expat libraries do not match, a build- or runtime link error or
|
|||
|
|
incompatibility might occur.</p></td></tr><tr><td width="5%" valign="top" align="left"><p><a href="#ex-subversion-nix-co-3">(3)</a> </p></td><td valign="top" align="left"><p>This assertion says that in order for Subversion to have SSL
|
|||
|
|
support (so that it can access <code class="literal">https</code> URLs), an
|
|||
|
|
OpenSSL library must be passed. Additionally, it says that
|
|||
|
|
<span class="emphasis"><em>if</em></span> Apache support is enabled, then Apache's
|
|||
|
|
OpenSSL should match Subversion's. (Note that if Apache support
|
|||
|
|
is not enabled, we don't care about Apache's OpenSSL.)</p></td></tr><tr><td width="5%" valign="top" align="left"><p><a href="#ex-subversion-nix-co-4">(4)</a> </p></td><td valign="top" align="left"><p>The conditional here is not really related to assertions,
|
|||
|
|
but is worth pointing out: it ensures that if SSL support is
|
|||
|
|
disabled, then the Subversion derivation is not dependent on
|
|||
|
|
OpenSSL, even if a non-<code class="literal">null</code> value was passed.
|
|||
|
|
This prevents an unnecessary rebuild of Subversion if OpenSSL
|
|||
|
|
changes.</p></td></tr></table></div></div><div class="simplesect"><div class="titlepage"><div><div><h3 class="title"><a id="idm139733301272384"></a>With-expressions</h3></div></div></div><p>A <span class="emphasis"><em>with-expression</em></span>,
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
with <em class="replaceable"><code>e1</code></em>; <em class="replaceable"><code>e2</code></em></pre><p>
|
|||
|
|
|
|||
|
|
introduces the set <em class="replaceable"><code>e1</code></em> into the lexical
|
|||
|
|
scope of the expression <em class="replaceable"><code>e2</code></em>. For instance,
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
let as = { x = "foo"; y = "bar"; };
|
|||
|
|
in with as; x + y</pre><p>
|
|||
|
|
|
|||
|
|
evaluates to <code class="literal">"foobar"</code> since the
|
|||
|
|
<code class="literal">with</code> adds the <code class="varname">x</code> and
|
|||
|
|
<code class="varname">y</code> attributes of <code class="varname">as</code> to the
|
|||
|
|
lexical scope in the expression <code class="literal">x + y</code>. The most
|
|||
|
|
common use of <code class="literal">with</code> is in conjunction with the
|
|||
|
|
<code class="function">import</code> function. E.g.,
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
with (import ./definitions.nix); ...</pre><p>
|
|||
|
|
|
|||
|
|
makes all attributes defined in the file
|
|||
|
|
<code class="filename">definitions.nix</code> available as if they were defined
|
|||
|
|
locally in a <code class="literal">let</code>-expression.</p><p>The bindings introduced by <code class="literal">with</code> do not shadow bindings
|
|||
|
|
introduced by other means, e.g.
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
let a = 3; in with { a = 1; }; let a = 4; in with { a = 2; }; ...</pre><p>
|
|||
|
|
|
|||
|
|
establishes the same scope as
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
let a = 1; in let a = 2; in let a = 3; in let a = 4; in ...</pre><p>
|
|||
|
|
|
|||
|
|
</p></div><div class="simplesect"><div class="titlepage"><div><div><h3 class="title"><a id="idm139733301261632"></a>Comments</h3></div></div></div><p>Comments can be single-line, started with a <code class="literal">#</code>
|
|||
|
|
character, or inline/multi-line, enclosed within <code class="literal">/*
|
|||
|
|
... */</code>.</p></div></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a id="sec-language-operators"></a>15.3. Operators</h2></div></div></div><p><a class="xref" href="#table-operators" title="Table 15.1. Operators">Table 15.1, “Operators”</a> lists the operators in the
|
|||
|
|
Nix expression language, in order of precedence (from strongest to
|
|||
|
|
weakest binding).</p><div class="table"><a id="table-operators"></a><p class="title"><strong>Table 15.1. Operators</strong></p><div class="table-contents"><table class="table" summary="Operators" border="1"><colgroup><col /><col /><col /></colgroup><thead><tr><th>Name</th><th>Syntax</th><th>Associativity</th><th>Description</th><th>Precedence</th></tr></thead><tbody><tr><td>Select</td><td><em class="replaceable"><code>e</code></em> <code class="literal">.</code>
|
|||
|
|
<em class="replaceable"><code>attrpath</code></em>
|
|||
|
|
[ <code class="literal">or</code> <em class="replaceable"><code>def</code></em> ]
|
|||
|
|
</td><td>none</td><td>Select attribute denoted by the attribute path
|
|||
|
|
<em class="replaceable"><code>attrpath</code></em> from set
|
|||
|
|
<em class="replaceable"><code>e</code></em>. (An attribute path is a
|
|||
|
|
dot-separated list of attribute names.) If the attribute
|
|||
|
|
doesn’t exist, return <em class="replaceable"><code>def</code></em> if
|
|||
|
|
provided, otherwise abort evaluation.</td><td>1</td></tr><tr><td>Application</td><td><em class="replaceable"><code>e1</code></em> <em class="replaceable"><code>e2</code></em></td><td>left</td><td>Call function <em class="replaceable"><code>e1</code></em> with
|
|||
|
|
argument <em class="replaceable"><code>e2</code></em>.</td><td>2</td></tr><tr><td>Arithmetic Negation</td><td><code class="literal">-</code> <em class="replaceable"><code>e</code></em></td><td>none</td><td>Arithmetic negation.</td><td>3</td></tr><tr><td>Has Attribute</td><td><em class="replaceable"><code>e</code></em> <code class="literal">?</code>
|
|||
|
|
<em class="replaceable"><code>attrpath</code></em></td><td>none</td><td>Test whether set <em class="replaceable"><code>e</code></em> contains
|
|||
|
|
the attribute denoted by <em class="replaceable"><code>attrpath</code></em>;
|
|||
|
|
return <code class="literal">true</code> or
|
|||
|
|
<code class="literal">false</code>.</td><td>4</td></tr><tr><td>List Concatenation</td><td><em class="replaceable"><code>e1</code></em> <code class="literal">++</code> <em class="replaceable"><code>e2</code></em></td><td>right</td><td>List concatenation.</td><td>5</td></tr><tr><td>Multiplication</td><td>
|
|||
|
|
<em class="replaceable"><code>e1</code></em> <code class="literal">*</code> <em class="replaceable"><code>e2</code></em>,
|
|||
|
|
</td><td>left</td><td>Arithmetic multiplication.</td><td>6</td></tr><tr><td>Division</td><td>
|
|||
|
|
<em class="replaceable"><code>e1</code></em> <code class="literal">/</code> <em class="replaceable"><code>e2</code></em>
|
|||
|
|
</td><td>left</td><td>Arithmetic division.</td><td>6</td></tr><tr><td>Addition</td><td>
|
|||
|
|
<em class="replaceable"><code>e1</code></em> <code class="literal">+</code> <em class="replaceable"><code>e2</code></em>
|
|||
|
|
</td><td>left</td><td>Arithmetic addition.</td><td>7</td></tr><tr><td>Subtraction</td><td>
|
|||
|
|
<em class="replaceable"><code>e1</code></em> <code class="literal">-</code> <em class="replaceable"><code>e2</code></em>
|
|||
|
|
</td><td>left</td><td>Arithmetic subtraction.</td><td>7</td></tr><tr><td>String Concatenation</td><td>
|
|||
|
|
<em class="replaceable"><code>string1</code></em> <code class="literal">+</code> <em class="replaceable"><code>string2</code></em>
|
|||
|
|
</td><td>left</td><td>String concatenation.</td><td>7</td></tr><tr><td>Not</td><td><code class="literal">!</code> <em class="replaceable"><code>e</code></em></td><td>none</td><td>Boolean negation.</td><td>8</td></tr><tr><td>Update</td><td><em class="replaceable"><code>e1</code></em> <code class="literal">//</code>
|
|||
|
|
<em class="replaceable"><code>e2</code></em></td><td>right</td><td>Return a set consisting of the attributes in
|
|||
|
|
<em class="replaceable"><code>e1</code></em> and
|
|||
|
|
<em class="replaceable"><code>e2</code></em> (with the latter taking
|
|||
|
|
precedence over the former in case of equally named
|
|||
|
|
attributes).</td><td>9</td></tr><tr><td>Less Than</td><td>
|
|||
|
|
<em class="replaceable"><code>e1</code></em> <code class="literal"><</code> <em class="replaceable"><code>e2</code></em>,
|
|||
|
|
</td><td>none</td><td>Arithmetic comparison.</td><td>10</td></tr><tr><td>Less Than or Equal To</td><td>
|
|||
|
|
<em class="replaceable"><code>e1</code></em> <code class="literal"><=</code> <em class="replaceable"><code>e2</code></em>
|
|||
|
|
</td><td>none</td><td>Arithmetic comparison.</td><td>10</td></tr><tr><td>Greater Than</td><td>
|
|||
|
|
<em class="replaceable"><code>e1</code></em> <code class="literal">></code> <em class="replaceable"><code>e2</code></em>
|
|||
|
|
</td><td>none</td><td>Arithmetic comparison.</td><td>10</td></tr><tr><td>Greater Than or Equal To</td><td>
|
|||
|
|
<em class="replaceable"><code>e1</code></em> <code class="literal">>=</code> <em class="replaceable"><code>e2</code></em>
|
|||
|
|
</td><td>none</td><td>Arithmetic comparison.</td><td>10</td></tr><tr><td>Equality</td><td>
|
|||
|
|
<em class="replaceable"><code>e1</code></em> <code class="literal">==</code> <em class="replaceable"><code>e2</code></em>
|
|||
|
|
</td><td>none</td><td>Equality.</td><td>11</td></tr><tr><td>Inequality</td><td>
|
|||
|
|
<em class="replaceable"><code>e1</code></em> <code class="literal">!=</code> <em class="replaceable"><code>e2</code></em>
|
|||
|
|
</td><td>none</td><td>Inequality.</td><td>11</td></tr><tr><td>Logical AND</td><td><em class="replaceable"><code>e1</code></em> <code class="literal">&&</code>
|
|||
|
|
<em class="replaceable"><code>e2</code></em></td><td>left</td><td>Logical AND.</td><td>12</td></tr><tr><td>Logical OR</td><td><em class="replaceable"><code>e1</code></em> <code class="literal">||</code>
|
|||
|
|
<em class="replaceable"><code>e2</code></em></td><td>left</td><td>Logical OR.</td><td>13</td></tr><tr><td>Logical Implication</td><td><em class="replaceable"><code>e1</code></em> <code class="literal">-></code>
|
|||
|
|
<em class="replaceable"><code>e2</code></em></td><td>none</td><td>Logical implication (equivalent to
|
|||
|
|
<code class="literal">!<em class="replaceable"><code>e1</code></em> ||
|
|||
|
|
<em class="replaceable"><code>e2</code></em></code>).</td><td>14</td></tr></tbody></table></div></div><br class="table-break" /></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a id="ssec-derivation"></a>15.4. Derivations</h2></div></div></div><p>The most important built-in function is
|
|||
|
|
<code class="function">derivation</code>, which is used to describe a single
|
|||
|
|
derivation (a build action). It takes as input a set, the attributes
|
|||
|
|
of which specify the inputs of the build.</p><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><p><a id="attr-system"></a>There must be an attribute named
|
|||
|
|
<code class="varname">system</code> whose value must be a string specifying a
|
|||
|
|
Nix platform identifier, such as <code class="literal">"i686-linux"</code> or
|
|||
|
|
<code class="literal">"x86_64-darwin"</code><a href="#ftn.idm139733301168656" class="footnote" id="idm139733301168656"><sup class="footnote">[7]</sup></a> The build
|
|||
|
|
can only be performed on a machine and operating system matching the
|
|||
|
|
platform identifier. (Nix can automatically forward builds for
|
|||
|
|
other platforms by forwarding them to other machines; see <a class="xref" href="#chap-distributed-builds" title="Chapter 16. Remote Builds">Chapter 16, <em>Remote Builds</em></a>.)</p></li><li class="listitem"><p>There must be an attribute named
|
|||
|
|
<code class="varname">name</code> whose value must be a string. This is used
|
|||
|
|
as a symbolic name for the package by <span class="command"><strong>nix-env</strong></span>,
|
|||
|
|
and it is appended to the output paths of the
|
|||
|
|
derivation.</p></li><li class="listitem"><p>There must be an attribute named
|
|||
|
|
<code class="varname">builder</code> that identifies the program that is
|
|||
|
|
executed to perform the build. It can be either a derivation or a
|
|||
|
|
source (a local file reference, e.g.,
|
|||
|
|
<code class="filename">./builder.sh</code>).</p></li><li class="listitem"><p>Every attribute is passed as an environment variable
|
|||
|
|
to the builder. Attribute values are translated to environment
|
|||
|
|
variables as follows:
|
|||
|
|
|
|||
|
|
</p><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: circle; "><li class="listitem"><p>Strings and numbers are just passed
|
|||
|
|
verbatim.</p></li><li class="listitem"><p>A <span class="emphasis"><em>path</em></span> (e.g.,
|
|||
|
|
<code class="filename">../foo/sources.tar</code>) causes the referenced
|
|||
|
|
file to be copied to the store; its location in the store is put
|
|||
|
|
in the environment variable. The idea is that all sources
|
|||
|
|
should reside in the Nix store, since all inputs to a derivation
|
|||
|
|
should reside in the Nix store.</p></li><li class="listitem"><p>A <span class="emphasis"><em>derivation</em></span> causes that
|
|||
|
|
derivation to be built prior to the present derivation; its
|
|||
|
|
default output path is put in the environment
|
|||
|
|
variable.</p></li><li class="listitem"><p>Lists of the previous types are also allowed.
|
|||
|
|
They are simply concatenated, separated by
|
|||
|
|
spaces.</p></li><li class="listitem"><p><code class="literal">true</code> is passed as the string
|
|||
|
|
<code class="literal">1</code>, <code class="literal">false</code> and
|
|||
|
|
<code class="literal">null</code> are passed as an empty string.
|
|||
|
|
</p></li></ul></div><p>
|
|||
|
|
|
|||
|
|
</p></li><li class="listitem"><p>The optional attribute <code class="varname">args</code>
|
|||
|
|
specifies command-line arguments to be passed to the builder. It
|
|||
|
|
should be a list.</p></li><li class="listitem"><p>The optional attribute <code class="varname">outputs</code>
|
|||
|
|
specifies a list of symbolic outputs of the derivation. By default,
|
|||
|
|
a derivation produces a single output path, denoted as
|
|||
|
|
<code class="literal">out</code>. However, derivations can produce multiple
|
|||
|
|
output paths. This is useful because it allows outputs to be
|
|||
|
|
downloaded or garbage-collected separately. For instance, imagine a
|
|||
|
|
library package that provides a dynamic library, header files, and
|
|||
|
|
documentation. A program that links against the library doesn’t
|
|||
|
|
need the header files and documentation at runtime, and it doesn’t
|
|||
|
|
need the documentation at build time. Thus, the library package
|
|||
|
|
could specify:
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
outputs = [ "lib" "headers" "doc" ];
|
|||
|
|
</pre><p>
|
|||
|
|
This will cause Nix to pass environment variables
|
|||
|
|
<code class="literal">lib</code>, <code class="literal">headers</code> and
|
|||
|
|
<code class="literal">doc</code> to the builder containing the intended store
|
|||
|
|
paths of each output. The builder would typically do something like
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
./configure --libdir=$lib/lib --includedir=$headers/include --docdir=$doc/share/doc
|
|||
|
|
</pre><p>
|
|||
|
|
for an Autoconf-style package. You can refer to each output of a
|
|||
|
|
derivation by selecting it as an attribute, e.g.
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
buildInputs = [ pkg.lib pkg.headers ];
|
|||
|
|
</pre><p>
|
|||
|
|
The first element of <code class="varname">outputs</code> determines the
|
|||
|
|
<span class="emphasis"><em>default output</em></span>. Thus, you could also write
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
buildInputs = [ pkg pkg.headers ];
|
|||
|
|
</pre><p>
|
|||
|
|
since <code class="literal">pkg</code> is equivalent to
|
|||
|
|
<code class="literal">pkg.lib</code>.</p></li></ul></div><p>The function <code class="function">mkDerivation</code> in the Nixpkgs
|
|||
|
|
standard environment is a wrapper around
|
|||
|
|
<code class="function">derivation</code> that adds a default value for
|
|||
|
|
<code class="varname">system</code> and always uses Bash as the builder, to
|
|||
|
|
which the supplied builder is passed as a command-line argument. See
|
|||
|
|
the Nixpkgs manual for details.</p><p>The builder is executed as follows:
|
|||
|
|
|
|||
|
|
</p><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><p>A temporary directory is created under the directory
|
|||
|
|
specified by <code class="envar">TMPDIR</code> (default
|
|||
|
|
<code class="filename">/tmp</code>) where the build will take place. The
|
|||
|
|
current directory is changed to this directory.</p></li><li class="listitem"><p>The environment is cleared and set to the derivation
|
|||
|
|
attributes, as specified above.</p></li><li class="listitem"><p>In addition, the following variables are set:
|
|||
|
|
|
|||
|
|
</p><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: circle; "><li class="listitem"><p><code class="envar">NIX_BUILD_TOP</code> contains the path of
|
|||
|
|
the temporary directory for this build.</p></li><li class="listitem"><p>Also, <code class="envar">TMPDIR</code>,
|
|||
|
|
<code class="envar">TEMPDIR</code>, <code class="envar">TMP</code>, <code class="envar">TEMP</code>
|
|||
|
|
are set to point to the temporary directory. This is to prevent
|
|||
|
|
the builder from accidentally writing temporary files anywhere
|
|||
|
|
else. Doing so might cause interference by other
|
|||
|
|
processes.</p></li><li class="listitem"><p><code class="envar">PATH</code> is set to
|
|||
|
|
<code class="filename">/path-not-set</code> to prevent shells from
|
|||
|
|
initialising it to their built-in default value.</p></li><li class="listitem"><p><code class="envar">HOME</code> is set to
|
|||
|
|
<code class="filename">/homeless-shelter</code> to prevent programs from
|
|||
|
|
using <code class="filename">/etc/passwd</code> or the like to find the
|
|||
|
|
user's home directory, which could cause impurity. Usually, when
|
|||
|
|
<code class="envar">HOME</code> is set, it is used as the location of the home
|
|||
|
|
directory, even if it points to a non-existent
|
|||
|
|
path.</p></li><li class="listitem"><p><code class="envar">NIX_STORE</code> is set to the path of the
|
|||
|
|
top-level Nix store directory (typically,
|
|||
|
|
<code class="filename">/nix/store</code>).</p></li><li class="listitem"><p>For each output declared in
|
|||
|
|
<code class="varname">outputs</code>, the corresponding environment variable
|
|||
|
|
is set to point to the intended path in the Nix store for that
|
|||
|
|
output. Each output path is a concatenation of the cryptographic
|
|||
|
|
hash of all build inputs, the <code class="varname">name</code> attribute
|
|||
|
|
and the output name. (The output name is omitted if it’s
|
|||
|
|
<code class="literal">out</code>.)</p></li></ul></div><p>
|
|||
|
|
|
|||
|
|
</p></li><li class="listitem"><p>If an output path already exists, it is removed.
|
|||
|
|
Also, locks are acquired to prevent multiple Nix instances from
|
|||
|
|
performing the same build at the same time.</p></li><li class="listitem"><p>A log of the combined standard output and error is
|
|||
|
|
written to <code class="filename">/nix/var/log/nix</code>.</p></li><li class="listitem"><p>The builder is executed with the arguments specified
|
|||
|
|
by the attribute <code class="varname">args</code>. If it exits with exit
|
|||
|
|
code 0, it is considered to have succeeded.</p></li><li class="listitem"><p>The temporary directory is removed (unless the
|
|||
|
|
<code class="option">-K</code> option was specified).</p></li><li class="listitem"><p>If the build was successful, Nix scans each output
|
|||
|
|
path for references to input paths by looking for the hash parts of
|
|||
|
|
the input paths. Since these are potential runtime dependencies,
|
|||
|
|
Nix registers them as dependencies of the output
|
|||
|
|
paths.</p></li><li class="listitem"><p>After the build, Nix sets the last-modified
|
|||
|
|
timestamp on all files in the build result to 1 (00:00:01 1/1/1970
|
|||
|
|
UTC), sets the group to the default group, and sets the mode of the
|
|||
|
|
file to 0444 or 0555 (i.e., read-only, with execute permission
|
|||
|
|
enabled if the file was originally executable). Note that possible
|
|||
|
|
<code class="literal">setuid</code> and <code class="literal">setgid</code> bits are
|
|||
|
|
cleared. Setuid and setgid programs are not currently supported by
|
|||
|
|
Nix. This is because the Nix archives used in deployment have no
|
|||
|
|
concept of ownership information, and because it makes the build
|
|||
|
|
result dependent on the user performing the build.</p></li></ul></div><p>
|
|||
|
|
|
|||
|
|
</p><div class="section"><div class="titlepage"><div><div><h3 class="title"><a id="sec-advanced-attributes"></a>15.4.1. Advanced Attributes</h3></div></div></div><p>Derivations can declare some infrequently used optional
|
|||
|
|
attributes.</p><div class="variablelist"><dl class="variablelist"><dt><a id="adv-attr-allowedReferences"></a><span class="term"><code class="varname">allowedReferences</code></span></dt><dd><p>The optional attribute
|
|||
|
|
<code class="varname">allowedReferences</code> specifies a list of legal
|
|||
|
|
references (dependencies) of the output of the builder. For
|
|||
|
|
example,
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
allowedReferences = [];
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
enforces that the output of a derivation cannot have any runtime
|
|||
|
|
dependencies on its inputs. To allow an output to have a runtime
|
|||
|
|
dependency on itself, use <code class="literal">"out"</code> as a list item.
|
|||
|
|
This is used in NixOS to check that generated files such as
|
|||
|
|
initial ramdisks for booting Linux don’t have accidental
|
|||
|
|
dependencies on other paths in the Nix store.</p></dd><dt><a id="adv-attr-allowedRequisites"></a><span class="term"><code class="varname">allowedRequisites</code></span></dt><dd><p>This attribute is similar to
|
|||
|
|
<code class="varname">allowedReferences</code>, but it specifies the legal
|
|||
|
|
requisites of the whole closure, so all the dependencies
|
|||
|
|
recursively. For example,
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
allowedRequisites = [ foobar ];
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
enforces that the output of a derivation cannot have any other
|
|||
|
|
runtime dependency than <code class="varname">foobar</code>, and in addition
|
|||
|
|
it enforces that <code class="varname">foobar</code> itself doesn't
|
|||
|
|
introduce any other dependency itself.</p></dd><dt><a id="adv-attr-disallowedReferences"></a><span class="term"><code class="varname">disallowedReferences</code></span></dt><dd><p>The optional attribute
|
|||
|
|
<code class="varname">disallowedReferences</code> specifies a list of illegal
|
|||
|
|
references (dependencies) of the output of the builder. For
|
|||
|
|
example,
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
disallowedReferences = [ foo ];
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
enforces that the output of a derivation cannot have a direct runtime
|
|||
|
|
dependencies on the derivation <code class="varname">foo</code>.</p></dd><dt><a id="adv-attr-disallowedRequisites"></a><span class="term"><code class="varname">disallowedRequisites</code></span></dt><dd><p>This attribute is similar to
|
|||
|
|
<code class="varname">disallowedReferences</code>, but it specifies illegal
|
|||
|
|
requisites for the whole closure, so all the dependencies
|
|||
|
|
recursively. For example,
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
disallowedRequisites = [ foobar ];
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
enforces that the output of a derivation cannot have any
|
|||
|
|
runtime dependency on <code class="varname">foobar</code> or any other derivation
|
|||
|
|
depending recursively on <code class="varname">foobar</code>.</p></dd><dt><a id="adv-attr-exportReferencesGraph"></a><span class="term"><code class="varname">exportReferencesGraph</code></span></dt><dd><p>This attribute allows builders access to the
|
|||
|
|
references graph of their inputs. The attribute is a list of
|
|||
|
|
inputs in the Nix store whose references graph the builder needs
|
|||
|
|
to know. The value of this attribute should be a list of pairs
|
|||
|
|
<code class="literal">[ <em class="replaceable"><code>name1</code></em>
|
|||
|
|
<em class="replaceable"><code>path1</code></em> <em class="replaceable"><code>name2</code></em>
|
|||
|
|
<em class="replaceable"><code>path2</code></em> <em class="replaceable"><code>...</code></em>
|
|||
|
|
]</code>. The references graph of each
|
|||
|
|
<em class="replaceable"><code>pathN</code></em> will be stored in a text file
|
|||
|
|
<em class="replaceable"><code>nameN</code></em> in the temporary build directory.
|
|||
|
|
The text files have the format used by <span class="command"><strong>nix-store
|
|||
|
|
--register-validity</strong></span> (with the deriver fields left
|
|||
|
|
empty). For example, when the following derivation is built:
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
derivation {
|
|||
|
|
...
|
|||
|
|
exportReferencesGraph = [ "libfoo-graph" libfoo ];
|
|||
|
|
};
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
the references graph of <code class="literal">libfoo</code> is placed in the
|
|||
|
|
file <code class="filename">libfoo-graph</code> in the temporary build
|
|||
|
|
directory.</p><p><code class="varname">exportReferencesGraph</code> is useful for
|
|||
|
|
builders that want to do something with the closure of a store
|
|||
|
|
path. Examples include the builders in NixOS that generate the
|
|||
|
|
initial ramdisk for booting Linux (a <span class="command"><strong>cpio</strong></span>
|
|||
|
|
archive containing the closure of the boot script) and the
|
|||
|
|
ISO-9660 image for the installation CD (which is populated with a
|
|||
|
|
Nix store containing the closure of a bootable NixOS
|
|||
|
|
configuration).</p></dd><dt><a id="adv-attr-impureEnvVars"></a><span class="term"><code class="varname">impureEnvVars</code></span></dt><dd><p>This attribute allows you to specify a list of
|
|||
|
|
environment variables that should be passed from the environment
|
|||
|
|
of the calling user to the builder. Usually, the environment is
|
|||
|
|
cleared completely when the builder is executed, but with this
|
|||
|
|
attribute you can allow specific environment variables to be
|
|||
|
|
passed unmodified. For example, <code class="function">fetchurl</code> in
|
|||
|
|
Nixpkgs has the line
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
impureEnvVars = [ "http_proxy" "https_proxy" <em class="replaceable"><code>...</code></em> ];
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
to make it use the proxy server configuration specified by the
|
|||
|
|
user in the environment variables <code class="envar">http_proxy</code> and
|
|||
|
|
friends.</p><p>This attribute is only allowed in <a class="link" href="#fixed-output-drvs">fixed-output derivations</a>, where
|
|||
|
|
impurities such as these are okay since (the hash of) the output
|
|||
|
|
is known in advance. It is ignored for all other
|
|||
|
|
derivations.</p><div class="warning"><h3 class="title">Warning</h3><p><code class="varname">impureEnvVars</code> implementation takes
|
|||
|
|
environment variables from the current builder process. When a daemon is
|
|||
|
|
building its environmental variables are used. Without the daemon, the
|
|||
|
|
environmental variables come from the environment of the
|
|||
|
|
<span class="command"><strong>nix-build</strong></span>.</p></div></dd><dt><a id="fixed-output-drvs"></a><span class="term"><a id="adv-attr-outputHash"></a><code class="varname">outputHash</code>, </span><span class="term"><a id="adv-attr-outputHashAlgo"></a><code class="varname">outputHashAlgo</code>, </span><span class="term"><a id="adv-attr-outputHashMode"></a><code class="varname">outputHashMode</code></span></dt><dd><p>These attributes declare that the derivation is a
|
|||
|
|
so-called <span class="emphasis"><em>fixed-output derivation</em></span>, which
|
|||
|
|
means that a cryptographic hash of the output is already known in
|
|||
|
|
advance. When the build of a fixed-output derivation finishes,
|
|||
|
|
Nix computes the cryptographic hash of the output and compares it
|
|||
|
|
to the hash declared with these attributes. If there is a
|
|||
|
|
mismatch, the build fails.</p><p>The rationale for fixed-output derivations is derivations
|
|||
|
|
such as those produced by the <code class="function">fetchurl</code>
|
|||
|
|
function. This function downloads a file from a given URL. To
|
|||
|
|
ensure that the downloaded file has not been modified, the caller
|
|||
|
|
must also specify a cryptographic hash of the file. For example,
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
fetchurl {
|
|||
|
|
url = "http://ftp.gnu.org/pub/gnu/hello/hello-2.1.1.tar.gz";
|
|||
|
|
sha256 = "1md7jsfd8pa45z73bz1kszpp01yw6x5ljkjk2hx7wl800any6465";
|
|||
|
|
}
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
It sometimes happens that the URL of the file changes, e.g.,
|
|||
|
|
because servers are reorganised or no longer available. We then
|
|||
|
|
must update the call to <code class="function">fetchurl</code>, e.g.,
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
fetchurl {
|
|||
|
|
url = "ftp://ftp.nluug.nl/pub/gnu/hello/hello-2.1.1.tar.gz";
|
|||
|
|
sha256 = "1md7jsfd8pa45z73bz1kszpp01yw6x5ljkjk2hx7wl800any6465";
|
|||
|
|
}
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
If a <code class="function">fetchurl</code> derivation was treated like a
|
|||
|
|
normal derivation, the output paths of the derivation and
|
|||
|
|
<span class="emphasis"><em>all derivations depending on it</em></span> would change.
|
|||
|
|
For instance, if we were to change the URL of the Glibc source
|
|||
|
|
distribution in Nixpkgs (a package on which almost all other
|
|||
|
|
packages depend) massive rebuilds would be needed. This is
|
|||
|
|
unfortunate for a change which we know cannot have a real effect
|
|||
|
|
as it propagates upwards through the dependency graph.</p><p>For fixed-output derivations, on the other hand, the name of
|
|||
|
|
the output path only depends on the <code class="varname">outputHash*</code>
|
|||
|
|
and <code class="varname">name</code> attributes, while all other attributes
|
|||
|
|
are ignored for the purpose of computing the output path. (The
|
|||
|
|
<code class="varname">name</code> attribute is included because it is part
|
|||
|
|
of the path.)</p><p>As an example, here is the (simplified) Nix expression for
|
|||
|
|
<code class="varname">fetchurl</code>:
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
{ stdenv, curl }: # The <span class="command"><strong>curl</strong></span> program is used for downloading.
|
|||
|
|
|
|||
|
|
{ url, sha256 }:
|
|||
|
|
|
|||
|
|
stdenv.mkDerivation {
|
|||
|
|
name = baseNameOf (toString url);
|
|||
|
|
builder = ./builder.sh;
|
|||
|
|
buildInputs = [ curl ];
|
|||
|
|
|
|||
|
|
# This is a fixed-output derivation; the output must be a regular
|
|||
|
|
# file with SHA256 hash <code class="varname">sha256</code>.
|
|||
|
|
outputHashMode = "flat";
|
|||
|
|
outputHashAlgo = "sha256";
|
|||
|
|
outputHash = sha256;
|
|||
|
|
|
|||
|
|
inherit url;
|
|||
|
|
}
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
</p><p>The <code class="varname">outputHashAlgo</code> attribute specifies
|
|||
|
|
the hash algorithm used to compute the hash. It can currently be
|
|||
|
|
<code class="literal">"sha1"</code>, <code class="literal">"sha256"</code> or
|
|||
|
|
<code class="literal">"sha512"</code>.</p><p>The <code class="varname">outputHashMode</code> attribute determines
|
|||
|
|
how the hash is computed. It must be one of the following two
|
|||
|
|
values:
|
|||
|
|
|
|||
|
|
</p><div class="variablelist"><dl class="variablelist"><dt><span class="term"><code class="literal">"flat"</code></span></dt><dd><p>The output must be a non-executable regular
|
|||
|
|
file. If it isn’t, the build fails. The hash is simply
|
|||
|
|
computed over the contents of that file (so it’s equal to what
|
|||
|
|
Unix commands like <span class="command"><strong>sha256sum</strong></span> or
|
|||
|
|
<span class="command"><strong>sha1sum</strong></span> produce).</p><p>This is the default.</p></dd><dt><span class="term"><code class="literal">"recursive"</code></span></dt><dd><p>The hash is computed over the NAR archive dump
|
|||
|
|
of the output (i.e., the result of <a class="link" href="#refsec-nix-store-dump" title="Operation --dump"><span class="command"><strong>nix-store
|
|||
|
|
--dump</strong></span></a>). In this case, the output can be
|
|||
|
|
anything, including a directory tree.</p></dd></dl></div><p>
|
|||
|
|
|
|||
|
|
</p><p>The <code class="varname">outputHash</code> attribute, finally, must
|
|||
|
|
be a string containing the hash in either hexadecimal or base-32
|
|||
|
|
notation. (See the <a class="link" href="#sec-nix-hash" title="nix-hash"><span class="command"><strong>nix-hash</strong></span> command</a>
|
|||
|
|
for information about converting to and from base-32
|
|||
|
|
notation.)</p></dd><dt><a id="adv-attr-passAsFile"></a><span class="term"><code class="varname">passAsFile</code></span></dt><dd><p>A list of names of attributes that should be
|
|||
|
|
passed via files rather than environment variables. For example,
|
|||
|
|
if you have
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
passAsFile = ["big"];
|
|||
|
|
big = "a very long string";
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
then when the builder runs, the environment variable
|
|||
|
|
<code class="envar">bigPath</code> will contain the absolute path to a
|
|||
|
|
temporary file containing <code class="literal">a very long
|
|||
|
|
string</code>. That is, for any attribute
|
|||
|
|
<em class="replaceable"><code>x</code></em> listed in
|
|||
|
|
<code class="varname">passAsFile</code>, Nix will pass an environment
|
|||
|
|
variable <code class="envar"><em class="replaceable"><code>x</code></em>Path</code> holding
|
|||
|
|
the path of the file containing the value of attribute
|
|||
|
|
<em class="replaceable"><code>x</code></em>. This is useful when you need to pass
|
|||
|
|
large strings to a builder, since most operating systems impose a
|
|||
|
|
limit on the size of the environment (typically, a few hundred
|
|||
|
|
kilobyte).</p></dd><dt><a id="adv-attr-preferLocalBuild"></a><span class="term"><code class="varname">preferLocalBuild</code></span></dt><dd><p>If this attribute is set to
|
|||
|
|
<code class="literal">true</code> and <a class="link" href="#chap-distributed-builds" title="Chapter 16. Remote Builds">distributed building is
|
|||
|
|
enabled</a>, then, if possible, the derivaton will be built
|
|||
|
|
locally instead of forwarded to a remote machine. This is
|
|||
|
|
appropriate for trivial builders where the cost of doing a
|
|||
|
|
download or remote build would exceed the cost of building
|
|||
|
|
locally.</p></dd><dt><a id="adv-attr-allowSubstitutes"></a><span class="term"><code class="varname">allowSubstitutes</code></span></dt><dd><p>If this attribute is set to
|
|||
|
|
<code class="literal">false</code>, then Nix will always build this
|
|||
|
|
derivation; it will not try to substitute its outputs. This is
|
|||
|
|
useful for very trivial derivations (such as
|
|||
|
|
<code class="function">writeText</code> in Nixpkgs) that are cheaper to
|
|||
|
|
build than to substitute from a binary cache.</p><div class="note"><h3 class="title">Note</h3><p>You need to have a builder configured which satisfies
|
|||
|
|
the derivation’s <code class="literal">system</code> attribute, since the
|
|||
|
|
derivation cannot be substituted. Thus it is usually a good idea
|
|||
|
|
to align <code class="literal">system</code> with
|
|||
|
|
<code class="literal">builtins.currentSystem</code> when setting
|
|||
|
|
<code class="literal">allowSubstitutes</code> to <code class="literal">false</code>.
|
|||
|
|
For most trivial derivations this should be the case.
|
|||
|
|
</p></div></dd></dl></div></div></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a id="ssec-builtins"></a>15.5. Built-in Functions</h2></div></div></div><p>This section lists the functions and constants built into the
|
|||
|
|
Nix expression evaluator. (The built-in function
|
|||
|
|
<code class="function">derivation</code> is discussed above.) Some built-ins,
|
|||
|
|
such as <code class="function">derivation</code>, are always in scope of every
|
|||
|
|
Nix expression; you can just access them right away. But to prevent
|
|||
|
|
polluting the namespace too much, most built-ins are not in scope.
|
|||
|
|
Instead, you can access them through the <code class="varname">builtins</code>
|
|||
|
|
built-in value, which is a set that contains all built-in functions
|
|||
|
|
and values. For instance, <code class="function">derivation</code> is also
|
|||
|
|
available as <code class="function">builtins.derivation</code>.</p><div class="variablelist"><dl class="variablelist"><dt><a id="builtin-abort"></a><span class="term"><code class="function">abort</code> <em class="replaceable"><code>s</code></em>, </span><span class="term"><code class="function">builtins.abort</code> <em class="replaceable"><code>s</code></em></span></dt><dd><p>Abort Nix expression evaluation, print error
|
|||
|
|
message <em class="replaceable"><code>s</code></em>.</p></dd><dt><a id="builtin-add"></a><span class="term"><code class="function">builtins.add</code>
|
|||
|
|
<em class="replaceable"><code>e1</code></em> <em class="replaceable"><code>e2</code></em>
|
|||
|
|
</span></dt><dd><p>Return the sum of the numbers
|
|||
|
|
<em class="replaceable"><code>e1</code></em> and
|
|||
|
|
<em class="replaceable"><code>e2</code></em>.</p></dd><dt><a id="builtin-all"></a><span class="term"><code class="function">builtins.all</code>
|
|||
|
|
<em class="replaceable"><code>pred</code></em> <em class="replaceable"><code>list</code></em></span></dt><dd><p>Return <code class="literal">true</code> if the function
|
|||
|
|
<em class="replaceable"><code>pred</code></em> returns <code class="literal">true</code>
|
|||
|
|
for all elements of <em class="replaceable"><code>list</code></em>,
|
|||
|
|
and <code class="literal">false</code> otherwise.</p></dd><dt><a id="builtin-any"></a><span class="term"><code class="function">builtins.any</code>
|
|||
|
|
<em class="replaceable"><code>pred</code></em> <em class="replaceable"><code>list</code></em></span></dt><dd><p>Return <code class="literal">true</code> if the function
|
|||
|
|
<em class="replaceable"><code>pred</code></em> returns <code class="literal">true</code>
|
|||
|
|
for at least one element of <em class="replaceable"><code>list</code></em>,
|
|||
|
|
and <code class="literal">false</code> otherwise.</p></dd><dt><a id="builtin-attrNames"></a><span class="term"><code class="function">builtins.attrNames</code>
|
|||
|
|
<em class="replaceable"><code>set</code></em></span></dt><dd><p>Return the names of the attributes in the set
|
|||
|
|
<em class="replaceable"><code>set</code></em> in an alphabetically sorted list. For instance,
|
|||
|
|
<code class="literal">builtins.attrNames { y = 1; x = "foo"; }</code>
|
|||
|
|
evaluates to <code class="literal">[ "x" "y" ]</code>.</p></dd><dt><a id="builtin-attrValues"></a><span class="term"><code class="function">builtins.attrValues</code>
|
|||
|
|
<em class="replaceable"><code>set</code></em></span></dt><dd><p>Return the values of the attributes in the set
|
|||
|
|
<em class="replaceable"><code>set</code></em> in the order corresponding to the
|
|||
|
|
sorted attribute names.</p></dd><dt><a id="builtin-baseNameOf"></a><span class="term"><code class="function">baseNameOf</code> <em class="replaceable"><code>s</code></em></span></dt><dd><p>Return the <span class="emphasis"><em>base name</em></span> of the
|
|||
|
|
string <em class="replaceable"><code>s</code></em>, that is, everything following
|
|||
|
|
the final slash in the string. This is similar to the GNU
|
|||
|
|
<span class="command"><strong>basename</strong></span> command.</p></dd><dt><a id="builtin-bitAnd"></a><span class="term"><code class="function">builtins.bitAnd</code>
|
|||
|
|
<em class="replaceable"><code>e1</code></em> <em class="replaceable"><code>e2</code></em></span></dt><dd><p>Return the bitwise AND of the integers
|
|||
|
|
<em class="replaceable"><code>e1</code></em> and
|
|||
|
|
<em class="replaceable"><code>e2</code></em>.</p></dd><dt><a id="builtin-bitOr"></a><span class="term"><code class="function">builtins.bitOr</code>
|
|||
|
|
<em class="replaceable"><code>e1</code></em> <em class="replaceable"><code>e2</code></em></span></dt><dd><p>Return the bitwise OR of the integers
|
|||
|
|
<em class="replaceable"><code>e1</code></em> and
|
|||
|
|
<em class="replaceable"><code>e2</code></em>.</p></dd><dt><a id="builtin-bitXor"></a><span class="term"><code class="function">builtins.bitXor</code>
|
|||
|
|
<em class="replaceable"><code>e1</code></em> <em class="replaceable"><code>e2</code></em></span></dt><dd><p>Return the bitwise XOR of the integers
|
|||
|
|
<em class="replaceable"><code>e1</code></em> and
|
|||
|
|
<em class="replaceable"><code>e2</code></em>.</p></dd><dt><a id="builtin-builtins"></a><span class="term"><code class="varname">builtins</code></span></dt><dd><p>The set <code class="varname">builtins</code> contains all
|
|||
|
|
the built-in functions and values. You can use
|
|||
|
|
<code class="varname">builtins</code> to test for the availability of
|
|||
|
|
features in the Nix installation, e.g.,
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
if builtins ? getEnv then builtins.getEnv "PATH" else ""</pre><p>
|
|||
|
|
|
|||
|
|
This allows a Nix expression to fall back gracefully on older Nix
|
|||
|
|
installations that don’t have the desired built-in
|
|||
|
|
function.</p></dd><dt><a id="builtin-compareVersions"></a><span class="term"><code class="function">builtins.compareVersions</code>
|
|||
|
|
<em class="replaceable"><code>s1</code></em> <em class="replaceable"><code>s2</code></em></span></dt><dd><p>Compare two strings representing versions and
|
|||
|
|
return <code class="literal">-1</code> if version
|
|||
|
|
<em class="replaceable"><code>s1</code></em> is older than version
|
|||
|
|
<em class="replaceable"><code>s2</code></em>, <code class="literal">0</code> if they are
|
|||
|
|
the same, and <code class="literal">1</code> if
|
|||
|
|
<em class="replaceable"><code>s1</code></em> is newer than
|
|||
|
|
<em class="replaceable"><code>s2</code></em>. The version comparison algorithm
|
|||
|
|
is the same as the one used by <a class="link" href="#ssec-version-comparisons" title="Versions"><span class="command"><strong>nix-env
|
|||
|
|
-u</strong></span></a>.</p></dd><dt><a id="builtin-concatLists"></a><span class="term"><code class="function">builtins.concatLists</code>
|
|||
|
|
<em class="replaceable"><code>lists</code></em></span></dt><dd><p>Concatenate a list of lists into a single
|
|||
|
|
list.</p></dd><dt><a id="builtin-concatStringsSep"></a><span class="term"><code class="function">builtins.concatStringsSep</code>
|
|||
|
|
<em class="replaceable"><code>separator</code></em> <em class="replaceable"><code>list</code></em></span></dt><dd><p>Concatenate a list of strings with a separator
|
|||
|
|
between each element, e.g. <code class="literal">concatStringsSep "/"
|
|||
|
|
["usr" "local" "bin"] == "usr/local/bin"</code></p></dd><dt><a id="builtin-currentSystem"></a><span class="term"><code class="varname">builtins.currentSystem</code></span></dt><dd><p>The built-in value <code class="varname">currentSystem</code>
|
|||
|
|
evaluates to the Nix platform identifier for the Nix installation
|
|||
|
|
on which the expression is being evaluated, such as
|
|||
|
|
<code class="literal">"i686-linux"</code> or
|
|||
|
|
<code class="literal">"x86_64-darwin"</code>.</p></dd><dt><a id="builtin-deepSeq"></a><span class="term"><code class="function">builtins.deepSeq</code>
|
|||
|
|
<em class="replaceable"><code>e1</code></em> <em class="replaceable"><code>e2</code></em></span></dt><dd><p>This is like <code class="literal">seq
|
|||
|
|
<em class="replaceable"><code>e1</code></em>
|
|||
|
|
<em class="replaceable"><code>e2</code></em></code>, except that
|
|||
|
|
<em class="replaceable"><code>e1</code></em> is evaluated
|
|||
|
|
<span class="emphasis"><em>deeply</em></span>: if it’s a list or set, its elements
|
|||
|
|
or attributes are also evaluated recursively.</p></dd><dt><a id="builtin-derivation"></a><span class="term"><code class="function">derivation</code>
|
|||
|
|
<em class="replaceable"><code>attrs</code></em>, </span><span class="term"><code class="function">builtins.derivation</code>
|
|||
|
|
<em class="replaceable"><code>attrs</code></em></span></dt><dd><p><code class="function">derivation</code> is described in
|
|||
|
|
<a class="xref" href="#ssec-derivation" title="15.4. Derivations">Section 15.4, “Derivations”</a>.</p></dd><dt><a id="builtin-dirOf"></a><span class="term"><code class="function">dirOf</code> <em class="replaceable"><code>s</code></em>, </span><span class="term"><code class="function">builtins.dirOf</code> <em class="replaceable"><code>s</code></em></span></dt><dd><p>Return the directory part of the string
|
|||
|
|
<em class="replaceable"><code>s</code></em>, that is, everything before the final
|
|||
|
|
slash in the string. This is similar to the GNU
|
|||
|
|
<span class="command"><strong>dirname</strong></span> command.</p></dd><dt><a id="builtin-div"></a><span class="term"><code class="function">builtins.div</code>
|
|||
|
|
<em class="replaceable"><code>e1</code></em> <em class="replaceable"><code>e2</code></em></span></dt><dd><p>Return the quotient of the numbers
|
|||
|
|
<em class="replaceable"><code>e1</code></em> and
|
|||
|
|
<em class="replaceable"><code>e2</code></em>.</p></dd><dt><a id="builtin-elem"></a><span class="term"><code class="function">builtins.elem</code>
|
|||
|
|
<em class="replaceable"><code>x</code></em> <em class="replaceable"><code>xs</code></em></span></dt><dd><p>Return <code class="literal">true</code> if a value equal to
|
|||
|
|
<em class="replaceable"><code>x</code></em> occurs in the list
|
|||
|
|
<em class="replaceable"><code>xs</code></em>, and <code class="literal">false</code>
|
|||
|
|
otherwise.</p></dd><dt><a id="builtin-elemAt"></a><span class="term"><code class="function">builtins.elemAt</code>
|
|||
|
|
<em class="replaceable"><code>xs</code></em> <em class="replaceable"><code>n</code></em></span></dt><dd><p>Return element <em class="replaceable"><code>n</code></em> from
|
|||
|
|
the list <em class="replaceable"><code>xs</code></em>. Elements are counted
|
|||
|
|
starting from 0. A fatal error occurs if the index is out of
|
|||
|
|
bounds.</p></dd><dt><a id="builtin-fetchurl"></a><span class="term"><code class="function">builtins.fetchurl</code>
|
|||
|
|
<em class="replaceable"><code>url</code></em></span></dt><dd><p>Download the specified URL and return the path of
|
|||
|
|
the downloaded file. This function is not available if <a class="link" href="#conf-restrict-eval">restricted evaluation mode</a> is
|
|||
|
|
enabled.</p></dd><dt><a id="builtin-fetchTarball"></a><span class="term"><code class="function">fetchTarball</code>
|
|||
|
|
<em class="replaceable"><code>url</code></em>, </span><span class="term"><code class="function">builtins.fetchTarball</code>
|
|||
|
|
<em class="replaceable"><code>url</code></em></span></dt><dd><p>Download the specified URL, unpack it and return
|
|||
|
|
the path of the unpacked tree. The file must be a tape archive
|
|||
|
|
(<code class="filename">.tar</code>) compressed with
|
|||
|
|
<code class="literal">gzip</code>, <code class="literal">bzip2</code> or
|
|||
|
|
<code class="literal">xz</code>. The top-level path component of the files
|
|||
|
|
in the tarball is removed, so it is best if the tarball contains a
|
|||
|
|
single directory at top level. The typical use of the function is
|
|||
|
|
to obtain external Nix expression dependencies, such as a
|
|||
|
|
particular version of Nixpkgs, e.g.
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
with import (fetchTarball https://github.com/NixOS/nixpkgs/archive/nixos-14.12.tar.gz) {};
|
|||
|
|
|
|||
|
|
stdenv.mkDerivation { … }
|
|||
|
|
</pre><p>
|
|||
|
|
</p><p>The fetched tarball is cached for a certain amount of time
|
|||
|
|
(1 hour by default) in <code class="filename">~/.cache/nix/tarballs/</code>.
|
|||
|
|
You can change the cache timeout either on the command line with
|
|||
|
|
<code class="option">--option tarball-ttl <em class="replaceable"><code>number of seconds</code></em></code> or
|
|||
|
|
in the Nix configuration file with this option:
|
|||
|
|
<code class="literal"><a class="xref" href="#conf-tarball-ttl"><code class="literal">tarball-ttl</code></a> <em class="replaceable"><code>number of seconds to cache</code></em></code>.
|
|||
|
|
</p><p>Note that when obtaining the hash with <code class="varname">nix-prefetch-url
|
|||
|
|
</code> the option <code class="varname">--unpack</code> is required.
|
|||
|
|
</p><p>This function can also verify the contents against a hash.
|
|||
|
|
In that case, the function takes a set instead of a URL. The set
|
|||
|
|
requires the attribute <code class="varname">url</code> and the attribute
|
|||
|
|
<code class="varname">sha256</code>, e.g.
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
with import (fetchTarball {
|
|||
|
|
url = "https://github.com/NixOS/nixpkgs/archive/nixos-14.12.tar.gz";
|
|||
|
|
sha256 = "1jppksrfvbk5ypiqdz4cddxdl8z6zyzdb2srq8fcffr327ld5jj2";
|
|||
|
|
}) {};
|
|||
|
|
|
|||
|
|
stdenv.mkDerivation { … }
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
</p><p>This function is not available if <a class="link" href="#conf-restrict-eval">restricted evaluation mode</a> is
|
|||
|
|
enabled.</p></dd><dt><a id="builtin-fetchGit"></a><span class="term">
|
|||
|
|
<code class="function">builtins.fetchGit</code>
|
|||
|
|
<em class="replaceable"><code>args</code></em>
|
|||
|
|
</span></dt><dd><p>
|
|||
|
|
Fetch a path from git. <em class="replaceable"><code>args</code></em> can be
|
|||
|
|
a URL, in which case the HEAD of the repo at that URL is
|
|||
|
|
fetched. Otherwise, it can be an attribute with the following
|
|||
|
|
attributes (all except <code class="varname">url</code> optional):
|
|||
|
|
</p><div class="variablelist"><dl class="variablelist"><dt><span class="term">url</span></dt><dd><p>
|
|||
|
|
The URL of the repo.
|
|||
|
|
</p></dd><dt><span class="term">name</span></dt><dd><p>
|
|||
|
|
The name of the directory the repo should be exported to
|
|||
|
|
in the store. Defaults to the basename of the URL.
|
|||
|
|
</p></dd><dt><span class="term">rev</span></dt><dd><p>
|
|||
|
|
The git revision to fetch. Defaults to the tip of
|
|||
|
|
<code class="varname">ref</code>.
|
|||
|
|
</p></dd><dt><span class="term">ref</span></dt><dd><p>
|
|||
|
|
The git ref to look for the requested revision under.
|
|||
|
|
This is often a branch or tag name. Defaults to
|
|||
|
|
<code class="literal">HEAD</code>.
|
|||
|
|
</p><p>
|
|||
|
|
By default, the <code class="varname">ref</code> value is prefixed
|
|||
|
|
with <code class="literal">refs/heads/</code>. As of Nix 2.3.0
|
|||
|
|
Nix will not prefix <code class="literal">refs/heads/</code> if
|
|||
|
|
<code class="varname">ref</code> starts with <code class="literal">refs/</code>.
|
|||
|
|
</p></dd><dt><span class="term">submodules</span></dt><dd><p>
|
|||
|
|
A Boolean parameter that specifies whether submodules
|
|||
|
|
should be checked out. Defaults to
|
|||
|
|
<code class="literal">false</code>.
|
|||
|
|
</p></dd></dl></div><div class="example"><a id="idm139733300931888"></a><p class="title"><strong>Example 15.2. Fetching a private repository over SSH</strong></p><div class="example-contents"><pre class="programlisting">builtins.fetchGit {
|
|||
|
|
url = "git@github.com:my-secret/repository.git";
|
|||
|
|
ref = "master";
|
|||
|
|
rev = "adab8b916a45068c044658c4158d81878f9ed1c3";
|
|||
|
|
}</pre></div></div><br class="example-break" /><div class="example"><a id="idm139733300930528"></a><p class="title"><strong>Example 15.3. Fetching an arbitrary ref</strong></p><div class="example-contents"><pre class="programlisting">builtins.fetchGit {
|
|||
|
|
url = "https://github.com/NixOS/nix.git";
|
|||
|
|
ref = "refs/heads/0.5-release";
|
|||
|
|
}</pre></div></div><br class="example-break" /><div class="example"><a id="idm139733300929216"></a><p class="title"><strong>Example 15.4. Fetching a repository's specific commit on an arbitrary branch</strong></p><div class="example-contents"><p>
|
|||
|
|
If the revision you're looking for is in the default branch
|
|||
|
|
of the git repository you don't strictly need to specify
|
|||
|
|
the branch name in the <code class="varname">ref</code> attribute.
|
|||
|
|
</p><p>
|
|||
|
|
However, if the revision you're looking for is in a future
|
|||
|
|
branch for the non-default branch you will need to specify
|
|||
|
|
the the <code class="varname">ref</code> attribute as well.
|
|||
|
|
</p><pre class="programlisting">builtins.fetchGit {
|
|||
|
|
url = "https://github.com/nixos/nix.git";
|
|||
|
|
rev = "841fcbd04755c7a2865c51c1e2d3b045976b7452";
|
|||
|
|
ref = "1.11-maintenance";
|
|||
|
|
}</pre><div class="note"><h3 class="title">Note</h3><p>
|
|||
|
|
It is nice to always specify the branch which a revision
|
|||
|
|
belongs to. Without the branch being specified, the
|
|||
|
|
fetcher might fail if the default branch changes.
|
|||
|
|
Additionally, it can be confusing to try a commit from a
|
|||
|
|
non-default branch and see the fetch fail. If the branch
|
|||
|
|
is specified the fault is much more obvious.
|
|||
|
|
</p></div></div></div><br class="example-break" /><div class="example"><a id="idm139733300924656"></a><p class="title"><strong>Example 15.5. Fetching a repository's specific commit on the default branch</strong></p><div class="example-contents"><p>
|
|||
|
|
If the revision you're looking for is in the default branch
|
|||
|
|
of the git repository you may omit the
|
|||
|
|
<code class="varname">ref</code> attribute.
|
|||
|
|
</p><pre class="programlisting">builtins.fetchGit {
|
|||
|
|
url = "https://github.com/nixos/nix.git";
|
|||
|
|
rev = "841fcbd04755c7a2865c51c1e2d3b045976b7452";
|
|||
|
|
}</pre></div></div><br class="example-break" /><div class="example"><a id="idm139733300922352"></a><p class="title"><strong>Example 15.6. Fetching a tag</strong></p><div class="example-contents"><pre class="programlisting">builtins.fetchGit {
|
|||
|
|
url = "https://github.com/nixos/nix.git";
|
|||
|
|
ref = "refs/tags/1.9";
|
|||
|
|
}</pre></div></div><br class="example-break" /><div class="example"><a id="idm139733300921056"></a><p class="title"><strong>Example 15.7. Fetching the latest version of a remote branch</strong></p><div class="example-contents"><p>
|
|||
|
|
<code class="function">builtins.fetchGit</code> can behave impurely
|
|||
|
|
fetch the latest version of a remote branch.
|
|||
|
|
</p><div class="note"><h3 class="title">Note</h3><p>Nix will refetch the branch in accordance to
|
|||
|
|
<a class="xref" href="#conf-tarball-ttl"><code class="literal">tarball-ttl</code></a>.</p></div><div class="note"><h3 class="title">Note</h3><p>This behavior is disabled in
|
|||
|
|
<span class="emphasis"><em>Pure evaluation mode</em></span>.</p></div><pre class="programlisting">builtins.fetchGit {
|
|||
|
|
url = "ssh://git@github.com/nixos/nix.git";
|
|||
|
|
ref = "master";
|
|||
|
|
}</pre></div></div><br class="example-break" /></dd><dt><span class="term"><code class="function">builtins.filter</code>
|
|||
|
|
<em class="replaceable"><code>f</code></em> <em class="replaceable"><code>xs</code></em></span></dt><dd><p>Return a list consisting of the elements of
|
|||
|
|
<em class="replaceable"><code>xs</code></em> for which the function
|
|||
|
|
<em class="replaceable"><code>f</code></em> returns
|
|||
|
|
<code class="literal">true</code>.</p></dd><dt><a id="builtin-filterSource"></a><span class="term"><code class="function">builtins.filterSource</code>
|
|||
|
|
<em class="replaceable"><code>e1</code></em> <em class="replaceable"><code>e2</code></em></span></dt><dd><p>This function allows you to copy sources into the Nix
|
|||
|
|
store while filtering certain files. For instance, suppose that
|
|||
|
|
you want to use the directory <code class="filename">source-dir</code> as
|
|||
|
|
an input to a Nix expression, e.g.
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
stdenv.mkDerivation {
|
|||
|
|
...
|
|||
|
|
src = ./source-dir;
|
|||
|
|
}
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
However, if <code class="filename">source-dir</code> is a Subversion
|
|||
|
|
working copy, then all those annoying <code class="filename">.svn</code>
|
|||
|
|
subdirectories will also be copied to the store. Worse, the
|
|||
|
|
contents of those directories may change a lot, causing lots of
|
|||
|
|
spurious rebuilds. With <code class="function">filterSource</code> you
|
|||
|
|
can filter out the <code class="filename">.svn</code> directories:
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
src = builtins.filterSource
|
|||
|
|
(path: type: type != "directory" || baseNameOf path != ".svn")
|
|||
|
|
./source-dir;
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
</p><p>Thus, the first argument <em class="replaceable"><code>e1</code></em>
|
|||
|
|
must be a predicate function that is called for each regular
|
|||
|
|
file, directory or symlink in the source tree
|
|||
|
|
<em class="replaceable"><code>e2</code></em>. If the function returns
|
|||
|
|
<code class="literal">true</code>, the file is copied to the Nix store,
|
|||
|
|
otherwise it is omitted. The function is called with two
|
|||
|
|
arguments. The first is the full path of the file. The second
|
|||
|
|
is a string that identifies the type of the file, which is
|
|||
|
|
either <code class="literal">"regular"</code>,
|
|||
|
|
<code class="literal">"directory"</code>, <code class="literal">"symlink"</code> or
|
|||
|
|
<code class="literal">"unknown"</code> (for other kinds of files such as
|
|||
|
|
device nodes or fifos — but note that those cannot be copied to
|
|||
|
|
the Nix store, so if the predicate returns
|
|||
|
|
<code class="literal">true</code> for them, the copy will fail). If you
|
|||
|
|
exclude a directory, the entire corresponding subtree of
|
|||
|
|
<em class="replaceable"><code>e2</code></em> will be excluded.</p></dd><dt><a id="builtin-foldl-prime"></a><span class="term"><code class="function">builtins.foldl’</code>
|
|||
|
|
<em class="replaceable"><code>op</code></em> <em class="replaceable"><code>nul</code></em> <em class="replaceable"><code>list</code></em></span></dt><dd><p>Reduce a list by applying a binary operator, from
|
|||
|
|
left to right, e.g. <code class="literal">foldl’ op nul [x0 x1 x2 ...] = op (op
|
|||
|
|
(op nul x0) x1) x2) ...</code>. The operator is applied
|
|||
|
|
strictly, i.e., its arguments are evaluated first. For example,
|
|||
|
|
<code class="literal">foldl’ (x: y: x + y) 0 [1 2 3]</code> evaluates to
|
|||
|
|
6.</p></dd><dt><a id="builtin-functionArgs"></a><span class="term"><code class="function">builtins.functionArgs</code>
|
|||
|
|
<em class="replaceable"><code>f</code></em></span></dt><dd><p>
|
|||
|
|
Return a set containing the names of the formal arguments expected
|
|||
|
|
by the function <em class="replaceable"><code>f</code></em>.
|
|||
|
|
The value of each attribute is a Boolean denoting whether the corresponding
|
|||
|
|
argument has a default value. For instance,
|
|||
|
|
<code class="literal">functionArgs ({ x, y ? 123}: ...) = { x = false; y = true; }</code>.
|
|||
|
|
</p><p>"Formal argument" here refers to the attributes pattern-matched by
|
|||
|
|
the function. Plain lambdas are not included, e.g.
|
|||
|
|
<code class="literal">functionArgs (x: ...) = { }</code>.
|
|||
|
|
</p></dd><dt><a id="builtin-fromJSON"></a><span class="term"><code class="function">builtins.fromJSON</code> <em class="replaceable"><code>e</code></em></span></dt><dd><p>Convert a JSON string to a Nix
|
|||
|
|
value. For example,
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
builtins.fromJSON ''{"x": [1, 2, 3], "y": null}''
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
returns the value <code class="literal">{ x = [ 1 2 3 ]; y = null;
|
|||
|
|
}</code>.</p></dd><dt><a id="builtin-genList"></a><span class="term"><code class="function">builtins.genList</code>
|
|||
|
|
<em class="replaceable"><code>generator</code></em> <em class="replaceable"><code>length</code></em></span></dt><dd><p>Generate list of size
|
|||
|
|
<em class="replaceable"><code>length</code></em>, with each element
|
|||
|
|
<em class="replaceable"><code>i</code></em> equal to the value returned by
|
|||
|
|
<em class="replaceable"><code>generator</code></em> <code class="literal">i</code>. For
|
|||
|
|
example,
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
builtins.genList (x: x * x) 5
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
returns the list <code class="literal">[ 0 1 4 9 16 ]</code>.</p></dd><dt><a id="builtin-getAttr"></a><span class="term"><code class="function">builtins.getAttr</code>
|
|||
|
|
<em class="replaceable"><code>s</code></em> <em class="replaceable"><code>set</code></em></span></dt><dd><p><code class="function">getAttr</code> returns the attribute
|
|||
|
|
named <em class="replaceable"><code>s</code></em> from
|
|||
|
|
<em class="replaceable"><code>set</code></em>. Evaluation aborts if the
|
|||
|
|
attribute doesn’t exist. This is a dynamic version of the
|
|||
|
|
<code class="literal">.</code> operator, since <em class="replaceable"><code>s</code></em>
|
|||
|
|
is an expression rather than an identifier.</p></dd><dt><a id="builtin-getEnv"></a><span class="term"><code class="function">builtins.getEnv</code>
|
|||
|
|
<em class="replaceable"><code>s</code></em></span></dt><dd><p><code class="function">getEnv</code> returns the value of
|
|||
|
|
the environment variable <em class="replaceable"><code>s</code></em>, or an empty
|
|||
|
|
string if the variable doesn’t exist. This function should be
|
|||
|
|
used with care, as it can introduce all sorts of nasty environment
|
|||
|
|
dependencies in your Nix expression.</p><p><code class="function">getEnv</code> is used in Nix Packages to
|
|||
|
|
locate the file <code class="filename">~/.nixpkgs/config.nix</code>, which
|
|||
|
|
contains user-local settings for Nix Packages. (That is, it does
|
|||
|
|
a <code class="literal">getEnv "HOME"</code> to locate the user’s home
|
|||
|
|
directory.)</p></dd><dt><a id="builtin-hasAttr"></a><span class="term"><code class="function">builtins.hasAttr</code>
|
|||
|
|
<em class="replaceable"><code>s</code></em> <em class="replaceable"><code>set</code></em></span></dt><dd><p><code class="function">hasAttr</code> returns
|
|||
|
|
<code class="literal">true</code> if <em class="replaceable"><code>set</code></em> has an
|
|||
|
|
attribute named <em class="replaceable"><code>s</code></em>, and
|
|||
|
|
<code class="literal">false</code> otherwise. This is a dynamic version of
|
|||
|
|
the <code class="literal">?</code> operator, since
|
|||
|
|
<em class="replaceable"><code>s</code></em> is an expression rather than an
|
|||
|
|
identifier.</p></dd><dt><a id="builtin-hashString"></a><span class="term"><code class="function">builtins.hashString</code>
|
|||
|
|
<em class="replaceable"><code>type</code></em> <em class="replaceable"><code>s</code></em></span></dt><dd><p>Return a base-16 representation of the
|
|||
|
|
cryptographic hash of string <em class="replaceable"><code>s</code></em>. The
|
|||
|
|
hash algorithm specified by <em class="replaceable"><code>type</code></em> must
|
|||
|
|
be one of <code class="literal">"md5"</code>, <code class="literal">"sha1"</code>,
|
|||
|
|
<code class="literal">"sha256"</code> or <code class="literal">"sha512"</code>.</p></dd><dt><a id="builtin-hashFile"></a><span class="term"><code class="function">builtins.hashFile</code>
|
|||
|
|
<em class="replaceable"><code>type</code></em> <em class="replaceable"><code>p</code></em></span></dt><dd><p>Return a base-16 representation of the
|
|||
|
|
cryptographic hash of the file at path <em class="replaceable"><code>p</code></em>. The
|
|||
|
|
hash algorithm specified by <em class="replaceable"><code>type</code></em> must
|
|||
|
|
be one of <code class="literal">"md5"</code>, <code class="literal">"sha1"</code>,
|
|||
|
|
<code class="literal">"sha256"</code> or <code class="literal">"sha512"</code>.</p></dd><dt><a id="builtin-head"></a><span class="term"><code class="function">builtins.head</code>
|
|||
|
|
<em class="replaceable"><code>list</code></em></span></dt><dd><p>Return the first element of a list; abort
|
|||
|
|
evaluation if the argument isn’t a list or is an empty list. You
|
|||
|
|
can test whether a list is empty by comparing it with
|
|||
|
|
<code class="literal">[]</code>.</p></dd><dt><a id="builtin-import"></a><span class="term"><code class="function">import</code>
|
|||
|
|
<em class="replaceable"><code>path</code></em>, </span><span class="term"><code class="function">builtins.import</code>
|
|||
|
|
<em class="replaceable"><code>path</code></em></span></dt><dd><p>Load, parse and return the Nix expression in the
|
|||
|
|
file <em class="replaceable"><code>path</code></em>. If <em class="replaceable"><code>path
|
|||
|
|
</code></em> is a directory, the file <code class="filename">default.nix
|
|||
|
|
</code> in that directory is loaded. Evaluation aborts if the
|
|||
|
|
file doesn’t exist or contains an incorrect Nix expression.
|
|||
|
|
<code class="function">import</code> implements Nix’s module system: you
|
|||
|
|
can put any Nix expression (such as a set or a function) in a
|
|||
|
|
separate file, and use it from Nix expressions in other
|
|||
|
|
files.</p><div class="note"><h3 class="title">Note</h3><p>Unlike some languages, <code class="function">import</code> is a regular
|
|||
|
|
function in Nix. Paths using the angle bracket syntax (e.g., <code class="function">
|
|||
|
|
import</code> <em class="replaceable"><code><foo></code></em>) are normal path
|
|||
|
|
values (see <a class="xref" href="#ssec-values" title="15.1. Values">Section 15.1, “Values”</a>).</p></div><p>A Nix expression loaded by <code class="function">import</code> must
|
|||
|
|
not contain any <span class="emphasis"><em>free variables</em></span> (identifiers
|
|||
|
|
that are not defined in the Nix expression itself and are not
|
|||
|
|
built-in). Therefore, it cannot refer to variables that are in
|
|||
|
|
scope at the call site. For instance, if you have a calling
|
|||
|
|
expression
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
rec {
|
|||
|
|
x = 123;
|
|||
|
|
y = import ./foo.nix;
|
|||
|
|
}</pre><p>
|
|||
|
|
|
|||
|
|
then the following <code class="filename">foo.nix</code> will give an
|
|||
|
|
error:
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
x + 456</pre><p>
|
|||
|
|
|
|||
|
|
since <code class="varname">x</code> is not in scope in
|
|||
|
|
<code class="filename">foo.nix</code>. If you want <code class="varname">x</code>
|
|||
|
|
to be available in <code class="filename">foo.nix</code>, you should pass
|
|||
|
|
it as a function argument:
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
rec {
|
|||
|
|
x = 123;
|
|||
|
|
y = import ./foo.nix x;
|
|||
|
|
}</pre><p>
|
|||
|
|
|
|||
|
|
and
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
x: x + 456</pre><p>
|
|||
|
|
|
|||
|
|
(The function argument doesn’t have to be called
|
|||
|
|
<code class="varname">x</code> in <code class="filename">foo.nix</code>; any name
|
|||
|
|
would work.)</p></dd><dt><a id="builtin-intersectAttrs"></a><span class="term"><code class="function">builtins.intersectAttrs</code>
|
|||
|
|
<em class="replaceable"><code>e1</code></em> <em class="replaceable"><code>e2</code></em></span></dt><dd><p>Return a set consisting of the attributes in the
|
|||
|
|
set <em class="replaceable"><code>e2</code></em> that also exist in the set
|
|||
|
|
<em class="replaceable"><code>e1</code></em>.</p></dd><dt><a id="builtin-isAttrs"></a><span class="term"><code class="function">builtins.isAttrs</code>
|
|||
|
|
<em class="replaceable"><code>e</code></em></span></dt><dd><p>Return <code class="literal">true</code> if
|
|||
|
|
<em class="replaceable"><code>e</code></em> evaluates to a set, and
|
|||
|
|
<code class="literal">false</code> otherwise.</p></dd><dt><a id="builtin-isList"></a><span class="term"><code class="function">builtins.isList</code>
|
|||
|
|
<em class="replaceable"><code>e</code></em></span></dt><dd><p>Return <code class="literal">true</code> if
|
|||
|
|
<em class="replaceable"><code>e</code></em> evaluates to a list, and
|
|||
|
|
<code class="literal">false</code> otherwise.</p></dd><dt><a id="builtin-isFunction"></a><span class="term"><code class="function">builtins.isFunction</code>
|
|||
|
|
<em class="replaceable"><code>e</code></em></span></dt><dd><p>Return <code class="literal">true</code> if
|
|||
|
|
<em class="replaceable"><code>e</code></em> evaluates to a function, and
|
|||
|
|
<code class="literal">false</code> otherwise.</p></dd><dt><a id="builtin-isString"></a><span class="term"><code class="function">builtins.isString</code>
|
|||
|
|
<em class="replaceable"><code>e</code></em></span></dt><dd><p>Return <code class="literal">true</code> if
|
|||
|
|
<em class="replaceable"><code>e</code></em> evaluates to a string, and
|
|||
|
|
<code class="literal">false</code> otherwise.</p></dd><dt><a id="builtin-isInt"></a><span class="term"><code class="function">builtins.isInt</code>
|
|||
|
|
<em class="replaceable"><code>e</code></em></span></dt><dd><p>Return <code class="literal">true</code> if
|
|||
|
|
<em class="replaceable"><code>e</code></em> evaluates to an int, and
|
|||
|
|
<code class="literal">false</code> otherwise.</p></dd><dt><a id="builtin-isFloat"></a><span class="term"><code class="function">builtins.isFloat</code>
|
|||
|
|
<em class="replaceable"><code>e</code></em></span></dt><dd><p>Return <code class="literal">true</code> if
|
|||
|
|
<em class="replaceable"><code>e</code></em> evaluates to a float, and
|
|||
|
|
<code class="literal">false</code> otherwise.</p></dd><dt><a id="builtin-isBool"></a><span class="term"><code class="function">builtins.isBool</code>
|
|||
|
|
<em class="replaceable"><code>e</code></em></span></dt><dd><p>Return <code class="literal">true</code> if
|
|||
|
|
<em class="replaceable"><code>e</code></em> evaluates to a bool, and
|
|||
|
|
<code class="literal">false</code> otherwise.</p></dd><dt><span class="term"><code class="function">builtins.isPath</code>
|
|||
|
|
<em class="replaceable"><code>e</code></em></span></dt><dd><p>Return <code class="literal">true</code> if
|
|||
|
|
<em class="replaceable"><code>e</code></em> evaluates to a path, and
|
|||
|
|
<code class="literal">false</code> otherwise.</p></dd><dt><a id="builtin-isNull"></a><span class="term"><code class="function">isNull</code>
|
|||
|
|
<em class="replaceable"><code>e</code></em>, </span><span class="term"><code class="function">builtins.isNull</code>
|
|||
|
|
<em class="replaceable"><code>e</code></em></span></dt><dd><p>Return <code class="literal">true</code> if
|
|||
|
|
<em class="replaceable"><code>e</code></em> evaluates to <code class="literal">null</code>,
|
|||
|
|
and <code class="literal">false</code> otherwise.</p><div class="warning"><h3 class="title">Warning</h3><p>This function is <span class="emphasis"><em>deprecated</em></span>;
|
|||
|
|
just write <code class="literal">e == null</code> instead.</p></div></dd><dt><a id="builtin-length"></a><span class="term"><code class="function">builtins.length</code>
|
|||
|
|
<em class="replaceable"><code>e</code></em></span></dt><dd><p>Return the length of the list
|
|||
|
|
<em class="replaceable"><code>e</code></em>.</p></dd><dt><a id="builtin-lessThan"></a><span class="term"><code class="function">builtins.lessThan</code>
|
|||
|
|
<em class="replaceable"><code>e1</code></em> <em class="replaceable"><code>e2</code></em></span></dt><dd><p>Return <code class="literal">true</code> if the number
|
|||
|
|
<em class="replaceable"><code>e1</code></em> is less than the number
|
|||
|
|
<em class="replaceable"><code>e2</code></em>, and <code class="literal">false</code>
|
|||
|
|
otherwise. Evaluation aborts if either
|
|||
|
|
<em class="replaceable"><code>e1</code></em> or <em class="replaceable"><code>e2</code></em>
|
|||
|
|
does not evaluate to a number.</p></dd><dt><a id="builtin-listToAttrs"></a><span class="term"><code class="function">builtins.listToAttrs</code>
|
|||
|
|
<em class="replaceable"><code>e</code></em></span></dt><dd><p>Construct a set from a list specifying the names
|
|||
|
|
and values of each attribute. Each element of the list should be
|
|||
|
|
a set consisting of a string-valued attribute
|
|||
|
|
<code class="varname">name</code> specifying the name of the attribute, and
|
|||
|
|
an attribute <code class="varname">value</code> specifying its value.
|
|||
|
|
Example:
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
builtins.listToAttrs
|
|||
|
|
[ { name = "foo"; value = 123; }
|
|||
|
|
{ name = "bar"; value = 456; }
|
|||
|
|
]
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
evaluates to
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
{ foo = 123; bar = 456; }
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
</p></dd><dt><a id="builtin-map"></a><span class="term"><code class="function">map</code>
|
|||
|
|
<em class="replaceable"><code>f</code></em> <em class="replaceable"><code>list</code></em>, </span><span class="term"><code class="function">builtins.map</code>
|
|||
|
|
<em class="replaceable"><code>f</code></em> <em class="replaceable"><code>list</code></em></span></dt><dd><p>Apply the function <em class="replaceable"><code>f</code></em> to
|
|||
|
|
each element in the list <em class="replaceable"><code>list</code></em>. For
|
|||
|
|
example,
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
map (x: "foo" + x) [ "bar" "bla" "abc" ]</pre><p>
|
|||
|
|
|
|||
|
|
evaluates to <code class="literal">[ "foobar" "foobla" "fooabc"
|
|||
|
|
]</code>.</p></dd><dt><a id="builtin-match"></a><span class="term"><code class="function">builtins.match</code>
|
|||
|
|
<em class="replaceable"><code>regex</code></em> <em class="replaceable"><code>str</code></em></span></dt><dd><p>Returns a list if the <a class="link" href="http://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap09.html#tag_09_04" target="_top">extended
|
|||
|
|
POSIX regular expression</a> <em class="replaceable"><code>regex</code></em>
|
|||
|
|
matches <em class="replaceable"><code>str</code></em> precisely, otherwise returns
|
|||
|
|
<code class="literal">null</code>. Each item in the list is a regex group.
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
builtins.match "ab" "abc"
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
Evaluates to <code class="literal">null</code>.
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
builtins.match "abc" "abc"
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
Evaluates to <code class="literal">[ ]</code>.
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
builtins.match "a(b)(c)" "abc"
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
Evaluates to <code class="literal">[ "b" "c" ]</code>.
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
builtins.match "[[:space:]]+([[:upper:]]+)[[:space:]]+" " FOO "
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
Evaluates to <code class="literal">[ "foo" ]</code>.
|
|||
|
|
|
|||
|
|
</p></dd><dt><a id="builtin-mul"></a><span class="term"><code class="function">builtins.mul</code>
|
|||
|
|
<em class="replaceable"><code>e1</code></em> <em class="replaceable"><code>e2</code></em></span></dt><dd><p>Return the product of the numbers
|
|||
|
|
<em class="replaceable"><code>e1</code></em> and
|
|||
|
|
<em class="replaceable"><code>e2</code></em>.</p></dd><dt><a id="builtin-parseDrvName"></a><span class="term"><code class="function">builtins.parseDrvName</code>
|
|||
|
|
<em class="replaceable"><code>s</code></em></span></dt><dd><p>Split the string <em class="replaceable"><code>s</code></em> into
|
|||
|
|
a package name and version. The package name is everything up to
|
|||
|
|
but not including the first dash followed by a digit, and the
|
|||
|
|
version is everything following that dash. The result is returned
|
|||
|
|
in a set <code class="literal">{ name, version }</code>. Thus,
|
|||
|
|
<code class="literal">builtins.parseDrvName "nix-0.12pre12876"</code>
|
|||
|
|
returns <code class="literal">{ name = "nix"; version = "0.12pre12876";
|
|||
|
|
}</code>.</p></dd><dt><a id="builtin-path"></a><span class="term">
|
|||
|
|
<code class="function">builtins.path</code>
|
|||
|
|
<em class="replaceable"><code>args</code></em>
|
|||
|
|
</span></dt><dd><p>
|
|||
|
|
An enrichment of the built-in path type, based on the attributes
|
|||
|
|
present in <em class="replaceable"><code>args</code></em>. All are optional
|
|||
|
|
except <code class="varname">path</code>:
|
|||
|
|
</p><div class="variablelist"><dl class="variablelist"><dt><span class="term">path</span></dt><dd><p>The underlying path.</p></dd><dt><span class="term">name</span></dt><dd><p>
|
|||
|
|
The name of the path when added to the store. This can
|
|||
|
|
used to reference paths that have nix-illegal characters
|
|||
|
|
in their names, like <code class="literal">@</code>.
|
|||
|
|
</p></dd><dt><span class="term">filter</span></dt><dd><p>
|
|||
|
|
A function of the type expected by
|
|||
|
|
<a class="link" href="#builtin-filterSource">builtins.filterSource</a>,
|
|||
|
|
with the same semantics.
|
|||
|
|
</p></dd><dt><span class="term">recursive</span></dt><dd><p>
|
|||
|
|
When <code class="literal">false</code>, when
|
|||
|
|
<code class="varname">path</code> is added to the store it is with a
|
|||
|
|
flat hash, rather than a hash of the NAR serialization of
|
|||
|
|
the file. Thus, <code class="varname">path</code> must refer to a
|
|||
|
|
regular file, not a directory. This allows similar
|
|||
|
|
behavior to <code class="literal">fetchurl</code>. Defaults to
|
|||
|
|
<code class="literal">true</code>.
|
|||
|
|
</p></dd><dt><span class="term">sha256</span></dt><dd><p>
|
|||
|
|
When provided, this is the expected hash of the file at
|
|||
|
|
the path. Evaluation will fail if the hash is incorrect,
|
|||
|
|
and providing a hash allows
|
|||
|
|
<code class="literal">builtins.path</code> to be used even when the
|
|||
|
|
<code class="literal">pure-eval</code> nix config option is on.
|
|||
|
|
</p></dd></dl></div></dd><dt><a id="builtin-pathExists"></a><span class="term"><code class="function">builtins.pathExists</code>
|
|||
|
|
<em class="replaceable"><code>path</code></em></span></dt><dd><p>Return <code class="literal">true</code> if the path
|
|||
|
|
<em class="replaceable"><code>path</code></em> exists at evaluation time, and
|
|||
|
|
<code class="literal">false</code> otherwise.</p></dd><dt><a id="builtin-placeholder"></a><span class="term"><code class="function">builtins.placeholder</code>
|
|||
|
|
<em class="replaceable"><code>output</code></em></span></dt><dd><p>Return a placeholder string for the specified
|
|||
|
|
<em class="replaceable"><code>output</code></em> that will be substituted by the
|
|||
|
|
corresponding output path at build time. Typical outputs would be
|
|||
|
|
<code class="literal">"out"</code>, <code class="literal">"bin"</code> or
|
|||
|
|
<code class="literal">"dev"</code>.</p></dd><dt><a id="builtin-readDir"></a><span class="term"><code class="function">builtins.readDir</code>
|
|||
|
|
<em class="replaceable"><code>path</code></em></span></dt><dd><p>Return the contents of the directory
|
|||
|
|
<em class="replaceable"><code>path</code></em> as a set mapping directory entries
|
|||
|
|
to the corresponding file type. For instance, if directory
|
|||
|
|
<code class="filename">A</code> contains a regular file
|
|||
|
|
<code class="filename">B</code> and another directory
|
|||
|
|
<code class="filename">C</code>, then <code class="literal">builtins.readDir
|
|||
|
|
./A</code> will return the set
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
{ B = "regular"; C = "directory"; }</pre><p>
|
|||
|
|
|
|||
|
|
The possible values for the file type are
|
|||
|
|
<code class="literal">"regular"</code>, <code class="literal">"directory"</code>,
|
|||
|
|
<code class="literal">"symlink"</code> and
|
|||
|
|
<code class="literal">"unknown"</code>.</p></dd><dt><a id="builtin-readFile"></a><span class="term"><code class="function">builtins.readFile</code>
|
|||
|
|
<em class="replaceable"><code>path</code></em></span></dt><dd><p>Return the contents of the file
|
|||
|
|
<em class="replaceable"><code>path</code></em> as a string.</p></dd><dt><a id="builtin-removeAttrs"></a><span class="term"><code class="function">removeAttrs</code>
|
|||
|
|
<em class="replaceable"><code>set</code></em> <em class="replaceable"><code>list</code></em>, </span><span class="term"><code class="function">builtins.removeAttrs</code>
|
|||
|
|
<em class="replaceable"><code>set</code></em> <em class="replaceable"><code>list</code></em></span></dt><dd><p>Remove the attributes listed in
|
|||
|
|
<em class="replaceable"><code>list</code></em> from
|
|||
|
|
<em class="replaceable"><code>set</code></em>. The attributes don’t have to
|
|||
|
|
exist in <em class="replaceable"><code>set</code></em>. For instance,
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
removeAttrs { x = 1; y = 2; z = 3; } [ "a" "x" "z" ]</pre><p>
|
|||
|
|
|
|||
|
|
evaluates to <code class="literal">{ y = 2; }</code>.</p></dd><dt><a id="builtin-replaceStrings"></a><span class="term"><code class="function">builtins.replaceStrings</code>
|
|||
|
|
<em class="replaceable"><code>from</code></em> <em class="replaceable"><code>to</code></em> <em class="replaceable"><code>s</code></em></span></dt><dd><p>Given string <em class="replaceable"><code>s</code></em>, replace
|
|||
|
|
every occurrence of the strings in <em class="replaceable"><code>from</code></em>
|
|||
|
|
with the corresponding string in
|
|||
|
|
<em class="replaceable"><code>to</code></em>. For example,
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
builtins.replaceStrings ["oo" "a"] ["a" "i"] "foobar"
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
evaluates to <code class="literal">"fabir"</code>.</p></dd><dt><a id="builtin-seq"></a><span class="term"><code class="function">builtins.seq</code>
|
|||
|
|
<em class="replaceable"><code>e1</code></em> <em class="replaceable"><code>e2</code></em></span></dt><dd><p>Evaluate <em class="replaceable"><code>e1</code></em>, then
|
|||
|
|
evaluate and return <em class="replaceable"><code>e2</code></em>. This ensures
|
|||
|
|
that a computation is strict in the value of
|
|||
|
|
<em class="replaceable"><code>e1</code></em>.</p></dd><dt><a id="builtin-sort"></a><span class="term"><code class="function">builtins.sort</code>
|
|||
|
|
<em class="replaceable"><code>comparator</code></em> <em class="replaceable"><code>list</code></em></span></dt><dd><p>Return <em class="replaceable"><code>list</code></em> in sorted
|
|||
|
|
order. It repeatedly calls the function
|
|||
|
|
<em class="replaceable"><code>comparator</code></em> with two elements. The
|
|||
|
|
comparator should return <code class="literal">true</code> if the first
|
|||
|
|
element is less than the second, and <code class="literal">false</code>
|
|||
|
|
otherwise. For example,
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
builtins.sort builtins.lessThan [ 483 249 526 147 42 77 ]
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
produces the list <code class="literal">[ 42 77 147 249 483 526
|
|||
|
|
]</code>.</p><p>This is a stable sort: it preserves the relative order of
|
|||
|
|
elements deemed equal by the comparator.</p></dd><dt><a id="builtin-split"></a><span class="term"><code class="function">builtins.split</code>
|
|||
|
|
<em class="replaceable"><code>regex</code></em> <em class="replaceable"><code>str</code></em></span></dt><dd><p>Returns a list composed of non matched strings interleaved
|
|||
|
|
with the lists of the <a class="link" href="http://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap09.html#tag_09_04" target="_top">extended
|
|||
|
|
POSIX regular expression</a> <em class="replaceable"><code>regex</code></em> matches
|
|||
|
|
of <em class="replaceable"><code>str</code></em>. Each item in the lists of matched
|
|||
|
|
sequences is a regex group.
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
builtins.split "(a)b" "abc"
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
Evaluates to <code class="literal">[ "" [ "a" ] "c" ]</code>.
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
builtins.split "([ac])" "abc"
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
Evaluates to <code class="literal">[ "" [ "a" ] "b" [ "c" ] "" ]</code>.
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
builtins.split "(a)|(c)" "abc"
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
Evaluates to <code class="literal">[ "" [ "a" null ] "b" [ null "c" ] "" ]</code>.
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
builtins.split "([[:upper:]]+)" " FOO "
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
Evaluates to <code class="literal">[ " " [ "FOO" ] " " ]</code>.
|
|||
|
|
|
|||
|
|
</p></dd><dt><a id="builtin-splitVersion"></a><span class="term"><code class="function">builtins.splitVersion</code>
|
|||
|
|
<em class="replaceable"><code>s</code></em></span></dt><dd><p>Split a string representing a version into its
|
|||
|
|
components, by the same version splitting logic underlying the
|
|||
|
|
version comparison in <a class="link" href="#ssec-version-comparisons" title="Versions">
|
|||
|
|
<span class="command"><strong>nix-env -u</strong></span></a>.</p></dd><dt><a id="builtin-stringLength"></a><span class="term"><code class="function">builtins.stringLength</code>
|
|||
|
|
<em class="replaceable"><code>e</code></em></span></dt><dd><p>Return the length of the string
|
|||
|
|
<em class="replaceable"><code>e</code></em>. If <em class="replaceable"><code>e</code></em> is
|
|||
|
|
not a string, evaluation is aborted.</p></dd><dt><a id="builtin-sub"></a><span class="term"><code class="function">builtins.sub</code>
|
|||
|
|
<em class="replaceable"><code>e1</code></em> <em class="replaceable"><code>e2</code></em></span></dt><dd><p>Return the difference between the numbers
|
|||
|
|
<em class="replaceable"><code>e1</code></em> and
|
|||
|
|
<em class="replaceable"><code>e2</code></em>.</p></dd><dt><a id="builtin-substring"></a><span class="term"><code class="function">builtins.substring</code>
|
|||
|
|
<em class="replaceable"><code>start</code></em> <em class="replaceable"><code>len</code></em>
|
|||
|
|
<em class="replaceable"><code>s</code></em></span></dt><dd><p>Return the substring of
|
|||
|
|
<em class="replaceable"><code>s</code></em> from character position
|
|||
|
|
<em class="replaceable"><code>start</code></em> (zero-based) up to but not
|
|||
|
|
including <em class="replaceable"><code>start + len</code></em>. If
|
|||
|
|
<em class="replaceable"><code>start</code></em> is greater than the length of the
|
|||
|
|
string, an empty string is returned, and if <em class="replaceable"><code>start +
|
|||
|
|
len</code></em> lies beyond the end of the string, only the
|
|||
|
|
substring up to the end of the string is returned.
|
|||
|
|
<em class="replaceable"><code>start</code></em> must be
|
|||
|
|
non-negative. For example,
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
builtins.substring 0 3 "nixos"
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
evaluates to <code class="literal">"nix"</code>.
|
|||
|
|
</p></dd><dt><a id="builtin-tail"></a><span class="term"><code class="function">builtins.tail</code>
|
|||
|
|
<em class="replaceable"><code>list</code></em></span></dt><dd><p>Return the second to last elements of a list;
|
|||
|
|
abort evaluation if the argument isn’t a list or is an empty
|
|||
|
|
list.</p></dd><dt><a id="builtin-throw"></a><span class="term"><code class="function">throw</code>
|
|||
|
|
<em class="replaceable"><code>s</code></em>, </span><span class="term"><code class="function">builtins.throw</code>
|
|||
|
|
<em class="replaceable"><code>s</code></em></span></dt><dd><p>Throw an error message
|
|||
|
|
<em class="replaceable"><code>s</code></em>. This usually aborts Nix expression
|
|||
|
|
evaluation, but in <span class="command"><strong>nix-env -qa</strong></span> and other
|
|||
|
|
commands that try to evaluate a set of derivations to get
|
|||
|
|
information about those derivations, a derivation that throws an
|
|||
|
|
error is silently skipped (which is not the case for
|
|||
|
|
<code class="function">abort</code>).</p></dd><dt><a id="builtin-toFile"></a><span class="term"><code class="function">builtins.toFile</code>
|
|||
|
|
<em class="replaceable"><code>name</code></em>
|
|||
|
|
<em class="replaceable"><code>s</code></em></span></dt><dd><p>Store the string <em class="replaceable"><code>s</code></em> in a
|
|||
|
|
file in the Nix store and return its path. The file has suffix
|
|||
|
|
<em class="replaceable"><code>name</code></em>. This file can be used as an
|
|||
|
|
input to derivations. One application is to write builders
|
|||
|
|
“inline”. For instance, the following Nix expression combines
|
|||
|
|
<a class="xref" href="#ex-hello-nix" title="Example 14.1. Nix expression for GNU Hello (default.nix)">Example 14.1, “Nix expression for GNU Hello
|
|||
|
|
(<code class="filename">default.nix</code>)”</a> and <a class="xref" href="#ex-hello-builder" title="Example 14.2. Build script for GNU Hello (builder.sh)">Example 14.2, “Build script for GNU Hello
|
|||
|
|
(<code class="filename">builder.sh</code>)”</a> into one file:
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
{ stdenv, fetchurl, perl }:
|
|||
|
|
|
|||
|
|
stdenv.mkDerivation {
|
|||
|
|
name = "hello-2.1.1";
|
|||
|
|
|
|||
|
|
builder = builtins.toFile "builder.sh" "
|
|||
|
|
source $stdenv/setup
|
|||
|
|
|
|||
|
|
PATH=$perl/bin:$PATH
|
|||
|
|
|
|||
|
|
tar xvfz $src
|
|||
|
|
cd hello-*
|
|||
|
|
./configure --prefix=$out
|
|||
|
|
make
|
|||
|
|
make install
|
|||
|
|
";
|
|||
|
|
|
|||
|
|
src = fetchurl {
|
|||
|
|
url = "http://ftp.nluug.nl/pub/gnu/hello/hello-2.1.1.tar.gz";
|
|||
|
|
sha256 = "1md7jsfd8pa45z73bz1kszpp01yw6x5ljkjk2hx7wl800any6465";
|
|||
|
|
};
|
|||
|
|
inherit perl;
|
|||
|
|
}</pre><p>
|
|||
|
|
|
|||
|
|
</p><p>It is even possible for one file to refer to another, e.g.,
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
builder = let
|
|||
|
|
configFile = builtins.toFile "foo.conf" "
|
|||
|
|
# This is some dummy configuration file.
|
|||
|
|
<em class="replaceable"><code>...</code></em>
|
|||
|
|
";
|
|||
|
|
in builtins.toFile "builder.sh" "
|
|||
|
|
source $stdenv/setup
|
|||
|
|
<em class="replaceable"><code>...</code></em>
|
|||
|
|
cp ${configFile} $out/etc/foo.conf
|
|||
|
|
";</pre><p>
|
|||
|
|
|
|||
|
|
Note that <code class="literal">${configFile}</code> is an antiquotation
|
|||
|
|
(see <a class="xref" href="#ssec-values" title="15.1. Values">Section 15.1, “Values”</a>), so the result of the
|
|||
|
|
expression <code class="literal">configFile</code> (i.e., a path like
|
|||
|
|
<code class="filename">/nix/store/m7p7jfny445k...-foo.conf</code>) will be
|
|||
|
|
spliced into the resulting string.</p><p>It is however <span class="emphasis"><em>not</em></span> allowed to have files
|
|||
|
|
mutually referring to each other, like so:
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
let
|
|||
|
|
foo = builtins.toFile "foo" "...${bar}...";
|
|||
|
|
bar = builtins.toFile "bar" "...${foo}...";
|
|||
|
|
in foo</pre><p>
|
|||
|
|
|
|||
|
|
This is not allowed because it would cause a cyclic dependency in
|
|||
|
|
the computation of the cryptographic hashes for
|
|||
|
|
<code class="varname">foo</code> and <code class="varname">bar</code>.</p><p>It is also not possible to reference the result of a derivation.
|
|||
|
|
If you are using Nixpkgs, the <code class="literal">writeTextFile</code> function is able to
|
|||
|
|
do that.</p></dd><dt><a id="builtin-toJSON"></a><span class="term"><code class="function">builtins.toJSON</code> <em class="replaceable"><code>e</code></em></span></dt><dd><p>Return a string containing a JSON representation
|
|||
|
|
of <em class="replaceable"><code>e</code></em>. Strings, integers, floats, booleans,
|
|||
|
|
nulls and lists are mapped to their JSON equivalents. Sets
|
|||
|
|
(except derivations) are represented as objects. Derivations are
|
|||
|
|
translated to a JSON string containing the derivation’s output
|
|||
|
|
path. Paths are copied to the store and represented as a JSON
|
|||
|
|
string of the resulting store path.</p></dd><dt><a id="builtin-toPath"></a><span class="term"><code class="function">builtins.toPath</code> <em class="replaceable"><code>s</code></em></span></dt><dd><p> DEPRECATED. Use <code class="literal">/. + "/path"</code>
|
|||
|
|
to convert a string into an absolute path. For relative paths,
|
|||
|
|
use <code class="literal">./. + "/path"</code>.
|
|||
|
|
</p></dd><dt><a id="builtin-toString"></a><span class="term"><code class="function">toString</code> <em class="replaceable"><code>e</code></em>, </span><span class="term"><code class="function">builtins.toString</code> <em class="replaceable"><code>e</code></em></span></dt><dd><p>Convert the expression
|
|||
|
|
<em class="replaceable"><code>e</code></em> to a string.
|
|||
|
|
<em class="replaceable"><code>e</code></em> can be:</p><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><p>A string (in which case the string is returned unmodified).</p></li><li class="listitem"><p>A path (e.g., <code class="literal">toString /foo/bar</code> yields <code class="literal">"/foo/bar"</code>.</p></li><li class="listitem"><p>A set containing <code class="literal">{ __toString = self: ...; }</code>.</p></li><li class="listitem"><p>An integer.</p></li><li class="listitem"><p>A list, in which case the string representations of its elements are joined with spaces.</p></li><li class="listitem"><p>A Boolean (<code class="literal">false</code> yields <code class="literal">""</code>, <code class="literal">true</code> yields <code class="literal">"1"</code>).</p></li><li class="listitem"><p><code class="literal">null</code>, which yields the empty string.</p></li></ul></div></dd><dt><a id="builtin-toXML"></a><span class="term"><code class="function">builtins.toXML</code> <em class="replaceable"><code>e</code></em></span></dt><dd><p>Return a string containing an XML representation
|
|||
|
|
of <em class="replaceable"><code>e</code></em>. The main application for
|
|||
|
|
<code class="function">toXML</code> is to communicate information with the
|
|||
|
|
builder in a more structured format than plain environment
|
|||
|
|
variables.</p><p><a class="xref" href="#ex-toxml" title="Example 15.8. Passing information to a builder using toXML">Example 15.8, “Passing information to a builder
|
|||
|
|
using <code class="function">toXML</code>”</a> shows an example where this is
|
|||
|
|
the case. The builder is supposed to generate the configuration
|
|||
|
|
file for a <a class="link" href="http://jetty.mortbay.org/" target="_top">Jetty
|
|||
|
|
servlet container</a>. A servlet container contains a number
|
|||
|
|
of servlets (<code class="filename">*.war</code> files) each exported under
|
|||
|
|
a specific URI prefix. So the servlet configuration is a list of
|
|||
|
|
sets containing the <code class="varname">path</code> and
|
|||
|
|
<code class="varname">war</code> of the servlet (<a class="xref" href="#ex-toxml-co-servlets">(3)</a>). This kind of information is
|
|||
|
|
difficult to communicate with the normal method of passing
|
|||
|
|
information through an environment variable, which just
|
|||
|
|
concatenates everything together into a string (which might just
|
|||
|
|
work in this case, but wouldn’t work if fields are optional or
|
|||
|
|
contain lists themselves). Instead the Nix expression is
|
|||
|
|
converted to an XML representation with
|
|||
|
|
<code class="function">toXML</code>, which is unambiguous and can easily be
|
|||
|
|
processed with the appropriate tools. For instance, in the
|
|||
|
|
example an XSLT stylesheet (<a class="xref" href="#ex-toxml-co-stylesheet">(2)</a>) is applied to it (<a class="xref" href="#ex-toxml-co-apply">(1)</a>) to
|
|||
|
|
generate the XML configuration file for the Jetty server. The XML
|
|||
|
|
representation produced from <a class="xref" href="#ex-toxml-co-servlets">(3)</a> by <code class="function">toXML</code> is shown in <a class="xref" href="#ex-toxml-result" title="Example 15.9. XML representation produced by toXML">Example 15.9, “XML representation produced by
|
|||
|
|
<code class="function">toXML</code>”</a>.</p><p>Note that <a class="xref" href="#ex-toxml" title="Example 15.8. Passing information to a builder using toXML">Example 15.8, “Passing information to a builder
|
|||
|
|
using <code class="function">toXML</code>”</a> uses the <code class="function"><a class="function" href="#builtin-toFile">toFile</a></code> built-in to write the
|
|||
|
|
builder and the stylesheet “inline” in the Nix expression. The
|
|||
|
|
path of the stylesheet is spliced into the builder at
|
|||
|
|
<code class="literal">xsltproc ${stylesheet}
|
|||
|
|
<em class="replaceable"><code>...</code></em></code>.</p><div class="example"><a id="ex-toxml"></a><p class="title"><strong>Example 15.8. Passing information to a builder
|
|||
|
|
using <code class="function">toXML</code></strong></p><div class="example-contents"><pre class="programlisting">
|
|||
|
|
{ stdenv, fetchurl, libxslt, jira, uberwiki }:
|
|||
|
|
|
|||
|
|
stdenv.mkDerivation (rec {
|
|||
|
|
name = "web-server";
|
|||
|
|
|
|||
|
|
buildInputs = [ libxslt ];
|
|||
|
|
|
|||
|
|
builder = builtins.toFile "builder.sh" "
|
|||
|
|
source $stdenv/setup
|
|||
|
|
mkdir $out
|
|||
|
|
echo "$servlets" | xsltproc ${stylesheet} - > $out/server-conf.xml <a id="ex-toxml-co-apply"></a>(1)
|
|||
|
|
";
|
|||
|
|
|
|||
|
|
stylesheet = builtins.toFile "stylesheet.xsl" <a id="ex-toxml-co-stylesheet"></a>(2)
|
|||
|
|
"<?xml version='1.0' encoding='UTF-8'?>
|
|||
|
|
<xsl:stylesheet xmlns:xsl='http://www.w3.org/1999/XSL/Transform' version='1.0'>
|
|||
|
|
<xsl:template match='/'>
|
|||
|
|
<Configure>
|
|||
|
|
<xsl:for-each select='/expr/list/attrs'>
|
|||
|
|
<Call name='addWebApplication'>
|
|||
|
|
<Arg><xsl:value-of select=\"attr[@name = 'path']/string/@value\" /></Arg>
|
|||
|
|
<Arg><xsl:value-of select=\"attr[@name = 'war']/path/@value\" /></Arg>
|
|||
|
|
</Call>
|
|||
|
|
</xsl:for-each>
|
|||
|
|
</Configure>
|
|||
|
|
</xsl:template>
|
|||
|
|
</xsl:stylesheet>
|
|||
|
|
";
|
|||
|
|
|
|||
|
|
servlets = builtins.toXML [ <a id="ex-toxml-co-servlets"></a>(3)
|
|||
|
|
{ path = "/bugtracker"; war = jira + "/lib/atlassian-jira.war"; }
|
|||
|
|
{ path = "/wiki"; war = uberwiki + "/uberwiki.war"; }
|
|||
|
|
];
|
|||
|
|
})</pre></div></div><br class="example-break" /><div class="example"><a id="ex-toxml-result"></a><p class="title"><strong>Example 15.9. XML representation produced by
|
|||
|
|
<code class="function">toXML</code></strong></p><div class="example-contents"><pre class="programlisting"><?xml version='1.0' encoding='utf-8'?>
|
|||
|
|
<expr>
|
|||
|
|
<list>
|
|||
|
|
<attrs>
|
|||
|
|
<attr name="path">
|
|||
|
|
<string value="/bugtracker" />
|
|||
|
|
</attr>
|
|||
|
|
<attr name="war">
|
|||
|
|
<path value="/nix/store/d1jh9pasa7k2...-jira/lib/atlassian-jira.war" />
|
|||
|
|
</attr>
|
|||
|
|
</attrs>
|
|||
|
|
<attrs>
|
|||
|
|
<attr name="path">
|
|||
|
|
<string value="/wiki" />
|
|||
|
|
</attr>
|
|||
|
|
<attr name="war">
|
|||
|
|
<path value="/nix/store/y6423b1yi4sx...-uberwiki/uberwiki.war" />
|
|||
|
|
</attr>
|
|||
|
|
</attrs>
|
|||
|
|
</list>
|
|||
|
|
</expr></pre></div></div><br class="example-break" /></dd><dt><a id="builtin-trace"></a><span class="term"><code class="function">builtins.trace</code>
|
|||
|
|
<em class="replaceable"><code>e1</code></em> <em class="replaceable"><code>e2</code></em></span></dt><dd><p>Evaluate <em class="replaceable"><code>e1</code></em> and print its
|
|||
|
|
abstract syntax representation on standard error. Then return
|
|||
|
|
<em class="replaceable"><code>e2</code></em>. This function is useful for
|
|||
|
|
debugging.</p></dd><dt><a id="builtin-tryEval"></a><span class="term"><code class="function">builtins.tryEval</code>
|
|||
|
|
<em class="replaceable"><code>e</code></em></span></dt><dd><p>Try to shallowly evaluate <em class="replaceable"><code>e</code></em>.
|
|||
|
|
Return a set containing the attributes <code class="literal">success</code>
|
|||
|
|
(<code class="literal">true</code> if <em class="replaceable"><code>e</code></em> evaluated
|
|||
|
|
successfully, <code class="literal">false</code> if an error was thrown) and
|
|||
|
|
<code class="literal">value</code>, equalling <em class="replaceable"><code>e</code></em>
|
|||
|
|
if successful and <code class="literal">false</code> otherwise. Note that this
|
|||
|
|
doesn't evaluate <em class="replaceable"><code>e</code></em> deeply, so
|
|||
|
|
<code class="literal">let e = { x = throw ""; }; in (builtins.tryEval e).success
|
|||
|
|
</code> will be <code class="literal">true</code>. Using <code class="literal">builtins.deepSeq
|
|||
|
|
</code> one can get the expected result: <code class="literal">let e = { x = throw "";
|
|||
|
|
}; in (builtins.tryEval (builtins.deepSeq e e)).success</code> will be
|
|||
|
|
<code class="literal">false</code>.
|
|||
|
|
</p></dd><dt><a id="builtin-typeOf"></a><span class="term"><code class="function">builtins.typeOf</code>
|
|||
|
|
<em class="replaceable"><code>e</code></em></span></dt><dd><p>Return a string representing the type of the value
|
|||
|
|
<em class="replaceable"><code>e</code></em>, namely <code class="literal">"int"</code>,
|
|||
|
|
<code class="literal">"bool"</code>, <code class="literal">"string"</code>,
|
|||
|
|
<code class="literal">"path"</code>, <code class="literal">"null"</code>,
|
|||
|
|
<code class="literal">"set"</code>, <code class="literal">"list"</code>,
|
|||
|
|
<code class="literal">"lambda"</code> or
|
|||
|
|
<code class="literal">"float"</code>.</p></dd></dl></div></div><div class="footnotes"><br /><hr style="width:100; text-align:left;margin-left: 0" /><div id="ftn.idm139733301368560" class="footnote"><p><a href="#idm139733301368560" class="para"><sup class="para">[5] </sup></a>It's parsed as an expression that selects the
|
|||
|
|
attribute <code class="varname">sh</code> from the variable
|
|||
|
|
<code class="varname">builder</code>.</p></div><div id="ftn.idm139733301331328" class="footnote"><p><a href="#idm139733301331328" class="para"><sup class="para">[6] </sup></a>Actually, Nix detects infinite
|
|||
|
|
recursion in this case and aborts (<span class="quote">“<span class="quote">infinite recursion
|
|||
|
|
encountered</span>”</span>).</p></div><div id="ftn.idm139733301168656" class="footnote"><p><a href="#idm139733301168656" class="para"><sup class="para">[7] </sup></a>To figure out
|
|||
|
|
your platform identifier, look at the line <span class="quote">“<span class="quote">Checking for the
|
|||
|
|
canonical Nix system name</span>”</span> in the output of Nix's
|
|||
|
|
<code class="filename">configure</code> script.</p></div></div></div></div><div class="part"><div class="titlepage"><div><div><h1 class="title"><a id="part-advanced-topics"></a>Part V. Advanced Topics</h1></div></div></div><div class="chapter"><div class="titlepage"><div><div><h2 class="title"><a id="chap-distributed-builds"></a>Chapter 16. Remote Builds</h2></div></div></div><p>Nix supports remote builds, where a local Nix installation can
|
|||
|
|
forward Nix builds to other machines. This allows multiple builds to
|
|||
|
|
be performed in parallel and allows Nix to perform multi-platform
|
|||
|
|
builds in a semi-transparent way. For instance, if you perform a
|
|||
|
|
build for a <code class="literal">x86_64-darwin</code> on an
|
|||
|
|
<code class="literal">i686-linux</code> machine, Nix can automatically forward
|
|||
|
|
the build to a <code class="literal">x86_64-darwin</code> machine, if
|
|||
|
|
available.</p><p>To forward a build to a remote machine, it’s required that the
|
|||
|
|
remote machine is accessible via SSH and that it has Nix
|
|||
|
|
installed. You can test whether connecting to the remote Nix instance
|
|||
|
|
works, e.g.
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix ping-store --store ssh://mac
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
will try to connect to the machine named <code class="literal">mac</code>. It is
|
|||
|
|
possible to specify an SSH identity file as part of the remote store
|
|||
|
|
URI, e.g.
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix ping-store --store ssh://mac?ssh-key=/home/alice/my-key
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
Since builds should be non-interactive, the key should not have a
|
|||
|
|
passphrase. Alternatively, you can load identities ahead of time into
|
|||
|
|
<span class="command"><strong>ssh-agent</strong></span> or <span class="command"><strong>gpg-agent</strong></span>.</p><p>If you get the error
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
bash: nix-store: command not found
|
|||
|
|
error: cannot connect to 'mac'
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
then you need to ensure that the <code class="envar">PATH</code> of
|
|||
|
|
non-interactive login shells contains Nix.</p><div class="warning"><h3 class="title">Warning</h3><p>If you are building via the Nix daemon, it is the Nix
|
|||
|
|
daemon user account (that is, <code class="literal">root</code>) that should
|
|||
|
|
have SSH access to the remote machine. If you can’t or don’t want to
|
|||
|
|
configure <code class="literal">root</code> to be able to access to remote
|
|||
|
|
machine, you can use a private Nix store instead by passing
|
|||
|
|
e.g. <code class="literal">--store ~/my-nix</code>.</p></div><p>The list of remote machines can be specified on the command line
|
|||
|
|
or in the Nix configuration file. The former is convenient for
|
|||
|
|
testing. For example, the following command allows you to build a
|
|||
|
|
derivation for <code class="literal">x86_64-darwin</code> on a Linux machine:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ uname
|
|||
|
|
Linux
|
|||
|
|
|
|||
|
|
$ nix build \
|
|||
|
|
'(with import <nixpkgs> { system = "x86_64-darwin"; }; runCommand "foo" {} "uname > $out")' \
|
|||
|
|
--builders 'ssh://mac x86_64-darwin'
|
|||
|
|
[1/0/1 built, 0.0 MiB DL] building foo on ssh://mac
|
|||
|
|
|
|||
|
|
$ cat ./result
|
|||
|
|
Darwin
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
It is possible to specify multiple builders separated by a semicolon
|
|||
|
|
or a newline, e.g.
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
--builders 'ssh://mac x86_64-darwin ; ssh://beastie x86_64-freebsd'
|
|||
|
|
</pre><p>
|
|||
|
|
</p><p>Each machine specification consists of the following elements,
|
|||
|
|
separated by spaces. Only the first element is required.
|
|||
|
|
To leave a field at its default, set it to <code class="literal">-</code>.
|
|||
|
|
|
|||
|
|
</p><div class="orderedlist"><ol class="orderedlist" type="1"><li class="listitem"><p>The URI of the remote store in the format
|
|||
|
|
<code class="literal">ssh://[<em class="replaceable"><code>username</code></em>@]<em class="replaceable"><code>hostname</code></em></code>,
|
|||
|
|
e.g. <code class="literal">ssh://nix@mac</code> or
|
|||
|
|
<code class="literal">ssh://mac</code>. For backward compatibility,
|
|||
|
|
<code class="literal">ssh://</code> may be omitted. The hostname may be an
|
|||
|
|
alias defined in your
|
|||
|
|
<code class="filename">~/.ssh/config</code>.</p></li><li class="listitem"><p>A comma-separated list of Nix platform type
|
|||
|
|
identifiers, such as <code class="literal">x86_64-darwin</code>. It is
|
|||
|
|
possible for a machine to support multiple platform types, e.g.,
|
|||
|
|
<code class="literal">i686-linux,x86_64-linux</code>. If omitted, this
|
|||
|
|
defaults to the local platform type.</p></li><li class="listitem"><p>The SSH identity file to be used to log in to the
|
|||
|
|
remote machine. If omitted, SSH will use its regular
|
|||
|
|
identities.</p></li><li class="listitem"><p>The maximum number of builds that Nix will execute
|
|||
|
|
in parallel on the machine. Typically this should be equal to the
|
|||
|
|
number of CPU cores. For instance, the machine
|
|||
|
|
<code class="literal">itchy</code> in the example will execute up to 8 builds
|
|||
|
|
in parallel.</p></li><li class="listitem"><p>The “speed factor”, indicating the relative speed of
|
|||
|
|
the machine. If there are multiple machines of the right type, Nix
|
|||
|
|
will prefer the fastest, taking load into account.</p></li><li class="listitem"><p>A comma-separated list of <span class="emphasis"><em>supported
|
|||
|
|
features</em></span>. If a derivation has the
|
|||
|
|
<code class="varname">requiredSystemFeatures</code> attribute, then Nix will
|
|||
|
|
only perform the derivation on a machine that has the specified
|
|||
|
|
features. For instance, the attribute
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
requiredSystemFeatures = [ "kvm" ];
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
will cause the build to be performed on a machine that has the
|
|||
|
|
<code class="literal">kvm</code> feature.</p></li><li class="listitem"><p>A comma-separated list of <span class="emphasis"><em>mandatory
|
|||
|
|
features</em></span>. A machine will only be used to build a
|
|||
|
|
derivation if all of the machine’s mandatory features appear in the
|
|||
|
|
derivation’s <code class="varname">requiredSystemFeatures</code>
|
|||
|
|
attribute..</p></li></ol></div><p>
|
|||
|
|
|
|||
|
|
For example, the machine specification
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
nix@scratchy.labs.cs.uu.nl i686-linux /home/nix/.ssh/id_scratchy_auto 8 1 kvm
|
|||
|
|
nix@itchy.labs.cs.uu.nl i686-linux /home/nix/.ssh/id_scratchy_auto 8 2
|
|||
|
|
nix@poochie.labs.cs.uu.nl i686-linux /home/nix/.ssh/id_scratchy_auto 1 2 kvm benchmark
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
specifies several machines that can perform
|
|||
|
|
<code class="literal">i686-linux</code> builds. However,
|
|||
|
|
<code class="literal">poochie</code> will only do builds that have the attribute
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
requiredSystemFeatures = [ "benchmark" ];
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
or
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
requiredSystemFeatures = [ "benchmark" "kvm" ];
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
<code class="literal">itchy</code> cannot do builds that require
|
|||
|
|
<code class="literal">kvm</code>, but <code class="literal">scratchy</code> does support
|
|||
|
|
such builds. For regular builds, <code class="literal">itchy</code> will be
|
|||
|
|
preferred over <code class="literal">scratchy</code> because it has a higher
|
|||
|
|
speed factor.</p><p>Remote builders can also be configured in
|
|||
|
|
<code class="filename">nix.conf</code>, e.g.
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
builders = ssh://mac x86_64-darwin ; ssh://beastie x86_64-freebsd
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
Finally, remote builders can be configured in a separate configuration
|
|||
|
|
file included in <code class="option">builders</code> via the syntax
|
|||
|
|
<code class="literal">@<em class="replaceable"><code>file</code></em></code>. For example,
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
builders = @/etc/nix/machines
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
causes the list of machines in <code class="filename">/etc/nix/machines</code>
|
|||
|
|
to be included. (This is the default.)</p><p>If you want the builders to use caches, you likely want to set
|
|||
|
|
the option <a class="link" href="#conf-builders-use-substitutes"><code class="literal">builders-use-substitutes</code></a>
|
|||
|
|
in your local <code class="filename">nix.conf</code>.</p><p>To build only on remote builders and disable building on the local machine,
|
|||
|
|
you can use the option <code class="option">--max-jobs 0</code>.</p></div><div class="chapter"><div class="titlepage"><div><div><h2 class="title"><a id="chap-tuning-cores-and-jobs"></a>Chapter 17. Tuning Cores and Jobs</h2></div></div></div><p>Nix has two relevant settings with regards to how your CPU cores
|
|||
|
|
will be utilized: <a class="xref" href="#conf-cores"><code class="literal">cores</code></a> and
|
|||
|
|
<a class="xref" href="#conf-max-jobs"><code class="literal">max-jobs</code></a>. This chapter will talk about what
|
|||
|
|
they are, how they interact, and their configuration trade-offs.</p><div class="variablelist"><dl class="variablelist"><dt><span class="term"><a class="xref" href="#conf-max-jobs"><code class="literal">max-jobs</code></a></span></dt><dd><p>
|
|||
|
|
Dictates how many separate derivations will be built at the same
|
|||
|
|
time. If you set this to zero, the local machine will do no
|
|||
|
|
builds. Nix will still substitute from binary caches, and build
|
|||
|
|
remotely if remote builders are configured.
|
|||
|
|
</p></dd><dt><span class="term"><a class="xref" href="#conf-cores"><code class="literal">cores</code></a></span></dt><dd><p>
|
|||
|
|
Suggests how many cores each derivation should use. Similar to
|
|||
|
|
<span class="command"><strong>make -j</strong></span>.
|
|||
|
|
</p></dd></dl></div><p>The <a class="xref" href="#conf-cores"><code class="literal">cores</code></a> setting determines the value of
|
|||
|
|
<code class="envar">NIX_BUILD_CORES</code>. <code class="envar">NIX_BUILD_CORES</code> is equal
|
|||
|
|
to <a class="xref" href="#conf-cores"><code class="literal">cores</code></a>, unless <a class="xref" href="#conf-cores"><code class="literal">cores</code></a>
|
|||
|
|
equals <code class="literal">0</code>, in which case <code class="envar">NIX_BUILD_CORES</code>
|
|||
|
|
will be the total number of cores in the system.</p><p>The maximum number of consumed cores is a simple multiplication,
|
|||
|
|
<a class="xref" href="#conf-max-jobs"><code class="literal">max-jobs</code></a> * <code class="envar">NIX_BUILD_CORES</code>.</p><p>The balance on how to set these two independent variables depends
|
|||
|
|
upon each builder's workload and hardware. Here are a few example
|
|||
|
|
scenarios on a machine with 24 cores:</p><div class="table"><a id="idm139733300537552"></a><p class="title"><strong>Table 17.1. Balancing 24 Build Cores</strong></p><div class="table-contents"><table><thead><tr>
|
|||
|
|
<th><a class="xref" href="#conf-max-jobs"><code class="literal">max-jobs</code></a></th>
|
|||
|
|
<th><a class="xref" href="#conf-cores"><code class="literal">cores</code></a></th>
|
|||
|
|
<th><code class="envar">NIX_BUILD_CORES</code></th>
|
|||
|
|
<th>Maximum Processes</th>
|
|||
|
|
<th>Result</th>
|
|||
|
|
</tr></thead><tbody><tr>
|
|||
|
|
<td>1</td>
|
|||
|
|
<td>24</td>
|
|||
|
|
<td>24</td>
|
|||
|
|
<td>24</td>
|
|||
|
|
<td>
|
|||
|
|
One derivation will be built at a time, each one can use 24
|
|||
|
|
cores. Undersold if a job can’t use 24 cores.
|
|||
|
|
</td>
|
|||
|
|
</tr><tr>
|
|||
|
|
<td>4</td>
|
|||
|
|
<td>6</td>
|
|||
|
|
<td>6</td>
|
|||
|
|
<td>24</td>
|
|||
|
|
<td>
|
|||
|
|
Four derivations will be built at once, each given access to
|
|||
|
|
six cores.
|
|||
|
|
</td>
|
|||
|
|
</tr><tr>
|
|||
|
|
<td>12</td>
|
|||
|
|
<td>6</td>
|
|||
|
|
<td>6</td>
|
|||
|
|
<td>72</td>
|
|||
|
|
<td>
|
|||
|
|
12 derivations will be built at once, each given access to six
|
|||
|
|
cores. This configuration is over-sold. If all 12 derivations
|
|||
|
|
being built simultaneously try to use all six cores, the
|
|||
|
|
machine's performance will be degraded due to extensive context
|
|||
|
|
switching between the 12 builds.
|
|||
|
|
</td>
|
|||
|
|
</tr><tr>
|
|||
|
|
<td>24</td>
|
|||
|
|
<td>1</td>
|
|||
|
|
<td>1</td>
|
|||
|
|
<td>24</td>
|
|||
|
|
<td>
|
|||
|
|
24 derivations can build at the same time, each using a single
|
|||
|
|
core. Never oversold, but derivations which require many cores
|
|||
|
|
will be very slow to compile.
|
|||
|
|
</td>
|
|||
|
|
</tr><tr>
|
|||
|
|
<td>24</td>
|
|||
|
|
<td>0</td>
|
|||
|
|
<td>24</td>
|
|||
|
|
<td>576</td>
|
|||
|
|
<td>
|
|||
|
|
24 derivations can build at the same time, each using all the
|
|||
|
|
available cores of the machine. Very likely to be oversold,
|
|||
|
|
and very likely to suffer context switches.
|
|||
|
|
</td>
|
|||
|
|
</tr></tbody></table></div></div><br class="table-break" /><p>It is up to the derivations' build script to respect
|
|||
|
|
host's requested cores-per-build by following the value of the
|
|||
|
|
<code class="envar">NIX_BUILD_CORES</code> environment variable.</p></div><div class="chapter"><div class="titlepage"><div><div><h2 class="title"><a id="chap-diff-hook"></a>Chapter 18. Verifying Build Reproducibility with <code class="option"><a class="option" href="#conf-diff-hook">diff-hook</a></code></h2></div><div><h3 class="subtitle"><em>Check build reproducibility by running builds multiple times
|
|||
|
|
and comparing their results.</em></h3></div></div></div><p>Specify a program with Nix's <a class="xref" href="#conf-diff-hook"><code class="literal">diff-hook</code></a> to
|
|||
|
|
compare build results when two builds produce different results. Note:
|
|||
|
|
this hook is only executed if the results are not the same, this hook
|
|||
|
|
is not used for determining if the results are the same.</p><p>For purposes of demonstration, we'll use the following Nix file,
|
|||
|
|
<code class="filename">deterministic.nix</code> for testing:</p><pre class="programlisting">
|
|||
|
|
let
|
|||
|
|
inherit (import <nixpkgs> {}) runCommand;
|
|||
|
|
in {
|
|||
|
|
stable = runCommand "stable" {} ''
|
|||
|
|
touch $out
|
|||
|
|
'';
|
|||
|
|
|
|||
|
|
unstable = runCommand "unstable" {} ''
|
|||
|
|
echo $RANDOM > $out
|
|||
|
|
'';
|
|||
|
|
}
|
|||
|
|
</pre><p>Additionally, <code class="filename">nix.conf</code> contains:
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
diff-hook = /etc/nix/my-diff-hook
|
|||
|
|
run-diff-hook = true
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
where <code class="filename">/etc/nix/my-diff-hook</code> is an executable
|
|||
|
|
file containing:
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
#!/bin/sh
|
|||
|
|
exec >&2
|
|||
|
|
echo "For derivation $3:"
|
|||
|
|
/run/current-system/sw/bin/diff -r "$1" "$2"
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
</p><p>The diff hook is executed by the same user and group who ran the
|
|||
|
|
build. However, the diff hook does not have write access to the store
|
|||
|
|
path just built.</p><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a id="idm139733300510624"></a>18.1.
|
|||
|
|
Spot-Checking Build Determinism
|
|||
|
|
</h2></div></div></div><p>
|
|||
|
|
Verify a path which already exists in the Nix store by passing
|
|||
|
|
<code class="option">--check</code> to the build command.
|
|||
|
|
</p><p>If the build passes and is deterministic, Nix will exit with a
|
|||
|
|
status code of 0:</p><pre class="screen">
|
|||
|
|
$ nix-build ./deterministic.nix -A stable
|
|||
|
|
this derivation will be built:
|
|||
|
|
/nix/store/z98fasz2jqy9gs0xbvdj939p27jwda38-stable.drv
|
|||
|
|
building '/nix/store/z98fasz2jqy9gs0xbvdj939p27jwda38-stable.drv'...
|
|||
|
|
/nix/store/yyxlzw3vqaas7wfp04g0b1xg51f2czgq-stable
|
|||
|
|
|
|||
|
|
$ nix-build ./deterministic.nix -A stable --check
|
|||
|
|
checking outputs of '/nix/store/z98fasz2jqy9gs0xbvdj939p27jwda38-stable.drv'...
|
|||
|
|
/nix/store/yyxlzw3vqaas7wfp04g0b1xg51f2czgq-stable
|
|||
|
|
</pre><p>If the build is not deterministic, Nix will exit with a status
|
|||
|
|
code of 1:</p><pre class="screen">
|
|||
|
|
$ nix-build ./deterministic.nix -A unstable
|
|||
|
|
this derivation will be built:
|
|||
|
|
/nix/store/cgl13lbj1w368r5z8gywipl1ifli7dhk-unstable.drv
|
|||
|
|
building '/nix/store/cgl13lbj1w368r5z8gywipl1ifli7dhk-unstable.drv'...
|
|||
|
|
/nix/store/krpqk0l9ib0ibi1d2w52z293zw455cap-unstable
|
|||
|
|
|
|||
|
|
$ nix-build ./deterministic.nix -A unstable --check
|
|||
|
|
checking outputs of '/nix/store/cgl13lbj1w368r5z8gywipl1ifli7dhk-unstable.drv'...
|
|||
|
|
error: derivation '/nix/store/cgl13lbj1w368r5z8gywipl1ifli7dhk-unstable.drv' may not be deterministic: output '/nix/store/krpqk0l9ib0ibi1d2w52z293zw455cap-unstable' differs
|
|||
|
|
</pre><p>In the Nix daemon's log, we will now see:
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
For derivation /nix/store/cgl13lbj1w368r5z8gywipl1ifli7dhk-unstable.drv:
|
|||
|
|
1c1
|
|||
|
|
< 8108
|
|||
|
|
---
|
|||
|
|
> 30204
|
|||
|
|
</pre><p>
|
|||
|
|
</p><p>Using <code class="option">--check</code> with <code class="option">--keep-failed</code>
|
|||
|
|
will cause Nix to keep the second build's output in a special,
|
|||
|
|
<code class="literal">.check</code> path:</p><pre class="screen">
|
|||
|
|
$ nix-build ./deterministic.nix -A unstable --check --keep-failed
|
|||
|
|
checking outputs of '/nix/store/cgl13lbj1w368r5z8gywipl1ifli7dhk-unstable.drv'...
|
|||
|
|
note: keeping build directory '/tmp/nix-build-unstable.drv-0'
|
|||
|
|
error: derivation '/nix/store/cgl13lbj1w368r5z8gywipl1ifli7dhk-unstable.drv' may not be deterministic: output '/nix/store/krpqk0l9ib0ibi1d2w52z293zw455cap-unstable' differs from '/nix/store/krpqk0l9ib0ibi1d2w52z293zw455cap-unstable.check'
|
|||
|
|
</pre><p>In particular, notice the
|
|||
|
|
<code class="literal">/nix/store/krpqk0l9ib0ibi1d2w52z293zw455cap-unstable.check</code>
|
|||
|
|
output. Nix has copied the build results to that directory where you
|
|||
|
|
can examine it.</p><div class="note"><h3 class="title"><a id="check-dirs-are-unregistered"></a><code class="literal">.check</code> paths are not registered store paths</h3><p>Check paths are not protected against garbage collection,
|
|||
|
|
and this path will be deleted on the next garbage collection.</p><p>The path is guaranteed to be alive for the duration of
|
|||
|
|
<a class="xref" href="#conf-diff-hook"><code class="literal">diff-hook</code></a>'s execution, but may be deleted
|
|||
|
|
any time after.</p><p>If the comparison is performed as part of automated tooling,
|
|||
|
|
please use the diff-hook or author your tooling to handle the case
|
|||
|
|
where the build was not deterministic and also a check path does
|
|||
|
|
not exist.</p></div><p>
|
|||
|
|
<code class="option">--check</code> is only usable if the derivation has
|
|||
|
|
been built on the system already. If the derivation has not been
|
|||
|
|
built Nix will fail with the error:
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
error: some outputs of '/nix/store/hzi1h60z2qf0nb85iwnpvrai3j2w7rr6-unstable.drv' are not valid, so checking is not possible
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
Run the build without <code class="option">--check</code>, and then try with
|
|||
|
|
<code class="option">--check</code> again.
|
|||
|
|
</p></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a id="idm139733300495744"></a>18.2.
|
|||
|
|
Automatic and Optionally Enforced Determinism Verification
|
|||
|
|
</h2></div></div></div><p>
|
|||
|
|
Automatically verify every build at build time by executing the
|
|||
|
|
build multiple times.
|
|||
|
|
</p><p>
|
|||
|
|
Setting <a class="xref" href="#conf-repeat"><code class="literal">repeat</code></a> and
|
|||
|
|
<a class="xref" href="#conf-enforce-determinism"><code class="literal">enforce-determinism</code></a> in your
|
|||
|
|
<code class="filename">nix.conf</code> permits the automated verification
|
|||
|
|
of every build Nix performs.
|
|||
|
|
</p><p>
|
|||
|
|
The following configuration will run each build three times, and
|
|||
|
|
will require the build to be deterministic:
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
enforce-determinism = true
|
|||
|
|
repeat = 2
|
|||
|
|
</pre><p>
|
|||
|
|
</p><p>
|
|||
|
|
Setting <a class="xref" href="#conf-enforce-determinism"><code class="literal">enforce-determinism</code></a> to false as in
|
|||
|
|
the following configuration will run the build multiple times,
|
|||
|
|
execute the build hook, but will allow the build to succeed even
|
|||
|
|
if it does not build reproducibly:
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
enforce-determinism = false
|
|||
|
|
repeat = 1
|
|||
|
|
</pre><p>
|
|||
|
|
</p><p>
|
|||
|
|
An example output of this configuration:
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-build ./test.nix -A unstable
|
|||
|
|
this derivation will be built:
|
|||
|
|
/nix/store/ch6llwpr2h8c3jmnf3f2ghkhx59aa97f-unstable.drv
|
|||
|
|
building '/nix/store/ch6llwpr2h8c3jmnf3f2ghkhx59aa97f-unstable.drv' (round 1/2)...
|
|||
|
|
building '/nix/store/ch6llwpr2h8c3jmnf3f2ghkhx59aa97f-unstable.drv' (round 2/2)...
|
|||
|
|
output '/nix/store/6xg356v9gl03hpbbg8gws77n19qanh02-unstable' of '/nix/store/ch6llwpr2h8c3jmnf3f2ghkhx59aa97f-unstable.drv' differs from '/nix/store/6xg356v9gl03hpbbg8gws77n19qanh02-unstable.check' from previous round
|
|||
|
|
/nix/store/6xg356v9gl03hpbbg8gws77n19qanh02-unstable
|
|||
|
|
</pre><p>
|
|||
|
|
</p></div></div><div class="chapter"><div class="titlepage"><div><div><h2 class="title"><a id="chap-post-build-hook"></a>Chapter 19. Using the <code class="option"><a class="option" href="#conf-post-build-hook">post-build-hook</a></code></h2></div><div><h3 class="subtitle"><em>Uploading to an S3-compatible binary cache after each build</em></h3></div></div></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a id="chap-post-build-hook-caveats"></a>19.1. Implementation Caveats</h2></div></div></div><p>Here we use the post-build hook to upload to a binary cache.
|
|||
|
|
This is a simple and working example, but it is not suitable for all
|
|||
|
|
use cases.</p><p>The post build hook program runs after each executed build,
|
|||
|
|
and blocks the build loop. The build loop exits if the hook program
|
|||
|
|
fails.</p><p>Concretely, this implementation will make Nix slow or unusable
|
|||
|
|
when the internet is slow or unreliable.</p><p>A more advanced implementation might pass the store paths to a
|
|||
|
|
user-supplied daemon or queue for processing the store paths outside
|
|||
|
|
of the build loop.</p></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a id="idm139733300481840"></a>19.2. Prerequisites</h2></div></div></div><p>
|
|||
|
|
This tutorial assumes you have configured an S3-compatible binary cache
|
|||
|
|
according to the instructions at
|
|||
|
|
<a class="xref" href="#ssec-s3-substituter-authenticated-writes" title="13.4.3. Authenticated Writes to your S3-compatible binary cache">Section 13.4.3, “Authenticated Writes to your S3-compatible binary cache”</a>, and
|
|||
|
|
that the <code class="literal">root</code> user's default AWS profile can
|
|||
|
|
upload to the bucket.
|
|||
|
|
</p></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a id="idm139733300479440"></a>19.3. Set up a Signing Key</h2></div></div></div><p>Use <span class="command"><strong>nix-store --generate-binary-cache-key</strong></span> to
|
|||
|
|
create our public and private signing keys. We will sign paths
|
|||
|
|
with the private key, and distribute the public key for verifying
|
|||
|
|
the authenticity of the paths.</p><pre class="screen">
|
|||
|
|
# nix-store --generate-binary-cache-key example-nix-cache-1 /etc/nix/key.private /etc/nix/key.public
|
|||
|
|
# cat /etc/nix/key.public
|
|||
|
|
example-nix-cache-1:1/cKDz3QCCOmwcztD2eV6Coggp6rqc9DGjWv7C0G+rM=
|
|||
|
|
</pre><p>Then, add the public key and the cache URL to your
|
|||
|
|
<code class="filename">nix.conf</code>'s <a class="xref" href="#conf-trusted-public-keys"><code class="literal">trusted-public-keys</code></a>
|
|||
|
|
and <a class="xref" href="#conf-substituters"><code class="literal">substituters</code></a> like:</p><pre class="programlisting">
|
|||
|
|
substituters = https://cache.nixos.org/ s3://example-nix-cache
|
|||
|
|
trusted-public-keys = cache.nixos.org-1:6NCHdD59X431o0gWypbMrAURkbJ16ZPMQFGspcDShjY= example-nix-cache-1:1/cKDz3QCCOmwcztD2eV6Coggp6rqc9DGjWv7C0G+rM=
|
|||
|
|
</pre><p>We will restart the Nix daemon in a later step.</p></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a id="idm139733300473952"></a>19.4. Implementing the build hook</h2></div></div></div><p>Write the following script to
|
|||
|
|
<code class="filename">/etc/nix/upload-to-cache.sh</code>:
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
#!/bin/sh
|
|||
|
|
|
|||
|
|
set -eu
|
|||
|
|
set -f # disable globbing
|
|||
|
|
export IFS=' '
|
|||
|
|
|
|||
|
|
echo "Signing paths" $OUT_PATHS
|
|||
|
|
nix sign-paths --key-file /etc/nix/key.private $OUT_PATHS
|
|||
|
|
echo "Uploading paths" $OUT_PATHS
|
|||
|
|
exec nix copy --to 's3://example-nix-cache' $OUT_PATHS
|
|||
|
|
</pre><div class="note"><h3 class="title">Should <code class="literal">$OUT_PATHS</code> be quoted?</h3><p>
|
|||
|
|
The <code class="literal">$OUT_PATHS</code> variable is a space-separated
|
|||
|
|
list of Nix store paths. In this case, we expect and want the
|
|||
|
|
shell to perform word splitting to make each output path its
|
|||
|
|
own argument to <span class="command"><strong>nix sign-paths</strong></span>. Nix guarantees
|
|||
|
|
the paths will not contain any spaces, however a store path
|
|||
|
|
might contain glob characters. The <span class="command"><strong>set -f</strong></span>
|
|||
|
|
disables globbing in the shell.
|
|||
|
|
</p></div><p>
|
|||
|
|
Then make sure the hook program is executable by the <code class="literal">root</code> user:
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
# chmod +x /etc/nix/upload-to-cache.sh
|
|||
|
|
</pre></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a id="idm139733300467040"></a>19.5. Updating Nix Configuration</h2></div></div></div><p>Edit <code class="filename">/etc/nix/nix.conf</code> to run our hook,
|
|||
|
|
by adding the following configuration snippet at the end:</p><pre class="programlisting">
|
|||
|
|
post-build-hook = /etc/nix/upload-to-cache.sh
|
|||
|
|
</pre><p>Then, restart the <span class="command"><strong>nix-daemon</strong></span>.</p></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a id="idm139733300464016"></a>19.6. Testing</h2></div></div></div><p>Build any derivation, for example:</p><pre class="screen">
|
|||
|
|
$ nix-build -E '(import <nixpkgs> {}).writeText "example" (builtins.toString builtins.currentTime)'
|
|||
|
|
this derivation will be built:
|
|||
|
|
/nix/store/s4pnfbkalzy5qz57qs6yybna8wylkig6-example.drv
|
|||
|
|
building '/nix/store/s4pnfbkalzy5qz57qs6yybna8wylkig6-example.drv'...
|
|||
|
|
running post-build-hook '/home/grahamc/projects/github.com/NixOS/nix/post-hook.sh'...
|
|||
|
|
post-build-hook: Signing paths /nix/store/ibcyipq5gf91838ldx40mjsp0b8w9n18-example
|
|||
|
|
post-build-hook: Uploading paths /nix/store/ibcyipq5gf91838ldx40mjsp0b8w9n18-example
|
|||
|
|
/nix/store/ibcyipq5gf91838ldx40mjsp0b8w9n18-example
|
|||
|
|
</pre><p>Then delete the path from the store, and try substituting it from the binary cache:</p><pre class="screen">
|
|||
|
|
$ rm ./result
|
|||
|
|
$ nix-store --delete /nix/store/ibcyipq5gf91838ldx40mjsp0b8w9n18-example
|
|||
|
|
</pre><p>Now, copy the path back from the cache:</p><pre class="screen">
|
|||
|
|
$ nix-store --realise /nix/store/ibcyipq5gf91838ldx40mjsp0b8w9n18-example
|
|||
|
|
copying path '/nix/store/m8bmqwrch6l3h8s0k3d673xpmipcdpsa-example from 's3://example-nix-cache'...
|
|||
|
|
warning: you did not specify '--add-root'; the result might be removed by the garbage collector
|
|||
|
|
/nix/store/m8bmqwrch6l3h8s0k3d673xpmipcdpsa-example
|
|||
|
|
</pre></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a id="idm139733300459088"></a>19.7. Conclusion</h2></div></div></div><p>
|
|||
|
|
We now have a Nix installation configured to automatically sign and
|
|||
|
|
upload every local build to a remote binary cache.
|
|||
|
|
</p><p>
|
|||
|
|
Before deploying this to production, be sure to consider the
|
|||
|
|
implementation caveats in <a class="xref" href="#chap-post-build-hook-caveats" title="19.1. Implementation Caveats">Section 19.1, “Implementation Caveats”</a>.
|
|||
|
|
</p></div></div></div><div class="part"><div class="titlepage"><div><div><h1 class="title"><a id="part-command-ref"></a>Part VI. Command Reference</h1></div></div></div><div class="partintro"><div></div><p>This section lists commands and options that you can use when you
|
|||
|
|
work with Nix.</p></div><div class="chapter"><div class="titlepage"><div><div><h2 class="title"><a id="sec-common-options"></a>Chapter 20. Common Options</h2></div></div></div><p>Most Nix commands accept the following command-line options:</p><div class="variablelist"><a id="opt-common"></a><dl class="variablelist"><dt><span class="term"><code class="option">--help</code></span></dt><dd><p>Prints out a summary of the command syntax and
|
|||
|
|
exits.</p></dd><dt><span class="term"><code class="option">--version</code></span></dt><dd><p>Prints out the Nix version number on standard output
|
|||
|
|
and exits.</p></dd><dt><span class="term"><code class="option">--verbose</code> / <code class="option">-v</code></span></dt><dd><p>Increases the level of verbosity of diagnostic messages
|
|||
|
|
printed on standard error. For each Nix operation, the information
|
|||
|
|
printed on standard output is well-defined; any diagnostic
|
|||
|
|
information is printed on standard error, never on standard
|
|||
|
|
output.</p><p>This option may be specified repeatedly. Currently, the
|
|||
|
|
following verbosity levels exist:</p><div class="variablelist"><dl class="variablelist"><dt><span class="term">0</span></dt><dd><p>“Errors only”: only print messages
|
|||
|
|
explaining why the Nix invocation failed.</p></dd><dt><span class="term">1</span></dt><dd><p>“Informational”: print
|
|||
|
|
<span class="emphasis"><em>useful</em></span> messages about what Nix is doing.
|
|||
|
|
This is the default.</p></dd><dt><span class="term">2</span></dt><dd><p>“Talkative”: print more informational
|
|||
|
|
messages.</p></dd><dt><span class="term">3</span></dt><dd><p>“Chatty”: print even more
|
|||
|
|
informational messages.</p></dd><dt><span class="term">4</span></dt><dd><p>“Debug”: print debug
|
|||
|
|
information.</p></dd><dt><span class="term">5</span></dt><dd><p>“Vomit”: print vast amounts of debug
|
|||
|
|
information.</p></dd></dl></div></dd><dt><span class="term"><code class="option">--quiet</code></span></dt><dd><p>Decreases the level of verbosity of diagnostic messages
|
|||
|
|
printed on standard error. This is the inverse option to
|
|||
|
|
<code class="option">-v</code> / <code class="option">--verbose</code>.
|
|||
|
|
</p><p>This option may be specified repeatedly. See the previous
|
|||
|
|
verbosity levels list.</p></dd><dt><a id="opt-log-format"></a><span class="term"><code class="option">--log-format</code> <em class="replaceable"><code>format</code></em></span></dt><dd><p>This option can be used to change the output of the log format, with
|
|||
|
|
<em class="replaceable"><code>format</code></em> being one of:</p><div class="variablelist"><dl class="variablelist"><dt><span class="term">raw</span></dt><dd><p>This is the raw format, as outputted by nix-build.</p></dd><dt><span class="term">internal-json</span></dt><dd><p>Outputs the logs in a structured manner. NOTE: the json schema is not guarantees to be stable between releases.</p></dd><dt><span class="term">bar</span></dt><dd><p>Only display a progress bar during the builds.</p></dd><dt><span class="term">bar-with-logs</span></dt><dd><p>Display the raw logs, with the progress bar at the bottom.</p></dd></dl></div></dd><dt><span class="term"><code class="option">--no-build-output</code> / <code class="option">-Q</code></span></dt><dd><p>By default, output written by builders to standard
|
|||
|
|
output and standard error is echoed to the Nix command's standard
|
|||
|
|
error. This option suppresses this behaviour. Note that the
|
|||
|
|
builder's standard output and error are always written to a log file
|
|||
|
|
in
|
|||
|
|
<code class="filename"><em class="replaceable"><code>prefix</code></em>/nix/var/log/nix</code>.</p></dd><dt><a id="opt-max-jobs"></a><span class="term"><code class="option">--max-jobs</code> / <code class="option">-j</code>
|
|||
|
|
<em class="replaceable"><code>number</code></em></span></dt><dd><p>Sets the maximum number of build jobs that Nix will
|
|||
|
|
perform in parallel to the specified number. Specify
|
|||
|
|
<code class="literal">auto</code> to use the number of CPUs in the system.
|
|||
|
|
The default is specified by the <a class="link" href="#conf-max-jobs"><code class="literal">max-jobs</code></a>
|
|||
|
|
configuration setting, which itself defaults to
|
|||
|
|
<code class="literal">1</code>. A higher value is useful on SMP systems or to
|
|||
|
|
exploit I/O latency.</p><p> Setting it to <code class="literal">0</code> disallows building on the local
|
|||
|
|
machine, which is useful when you want builds to happen only on remote
|
|||
|
|
builders.</p></dd><dt><a id="opt-cores"></a><span class="term"><code class="option">--cores</code></span></dt><dd><p>Sets the value of the <code class="envar">NIX_BUILD_CORES</code>
|
|||
|
|
environment variable in the invocation of builders. Builders can
|
|||
|
|
use this variable at their discretion to control the maximum amount
|
|||
|
|
of parallelism. For instance, in Nixpkgs, if the derivation
|
|||
|
|
attribute <code class="varname">enableParallelBuilding</code> is set to
|
|||
|
|
<code class="literal">true</code>, the builder passes the
|
|||
|
|
<code class="option">-j<em class="replaceable"><code>N</code></em></code> flag to GNU Make.
|
|||
|
|
It defaults to the value of the <a class="link" href="#conf-cores"><code class="literal">cores</code></a>
|
|||
|
|
configuration setting, if set, or <code class="literal">1</code> otherwise.
|
|||
|
|
The value <code class="literal">0</code> means that the builder should use all
|
|||
|
|
available CPU cores in the system.</p></dd><dt><a id="opt-max-silent-time"></a><span class="term"><code class="option">--max-silent-time</code></span></dt><dd><p>Sets the maximum number of seconds that a builder
|
|||
|
|
can go without producing any data on standard output or standard
|
|||
|
|
error. The default is specified by the <a class="link" href="#conf-max-silent-time"><code class="literal">max-silent-time</code></a>
|
|||
|
|
configuration setting. <code class="literal">0</code> means no
|
|||
|
|
time-out.</p></dd><dt><a id="opt-timeout"></a><span class="term"><code class="option">--timeout</code></span></dt><dd><p>Sets the maximum number of seconds that a builder
|
|||
|
|
can run. The default is specified by the <a class="link" href="#conf-timeout"><code class="literal">timeout</code></a>
|
|||
|
|
configuration setting. <code class="literal">0</code> means no
|
|||
|
|
timeout.</p></dd><dt><span class="term"><code class="option">--keep-going</code> / <code class="option">-k</code></span></dt><dd><p>Keep going in case of failed builds, to the
|
|||
|
|
greatest extent possible. That is, if building an input of some
|
|||
|
|
derivation fails, Nix will still build the other inputs, but not the
|
|||
|
|
derivation itself. Without this option, Nix stops if any build
|
|||
|
|
fails (except for builds of substitutes), possibly killing builds in
|
|||
|
|
progress (in case of parallel or distributed builds).</p></dd><dt><span class="term"><code class="option">--keep-failed</code> / <code class="option">-K</code></span></dt><dd><p>Specifies that in case of a build failure, the
|
|||
|
|
temporary directory (usually in <code class="filename">/tmp</code>) in which
|
|||
|
|
the build takes place should not be deleted. The path of the build
|
|||
|
|
directory is printed as an informational message.
|
|||
|
|
</p></dd><dt><span class="term"><code class="option">--fallback</code></span></dt><dd><p>Whenever Nix attempts to build a derivation for which
|
|||
|
|
substitutes are known for each output path, but realising the output
|
|||
|
|
paths through the substitutes fails, fall back on building the
|
|||
|
|
derivation.</p><p>The most common scenario in which this is useful is when we
|
|||
|
|
have registered substitutes in order to perform binary distribution
|
|||
|
|
from, say, a network repository. If the repository is down, the
|
|||
|
|
realisation of the derivation will fail. When this option is
|
|||
|
|
specified, Nix will build the derivation instead. Thus,
|
|||
|
|
installation from binaries falls back on installation from source.
|
|||
|
|
This option is not the default since it is generally not desirable
|
|||
|
|
for a transient failure in obtaining the substitutes to lead to a
|
|||
|
|
full build from source (with the related consumption of
|
|||
|
|
resources).</p></dd><dt><span class="term"><code class="option">--no-build-hook</code></span></dt><dd><p>Disables the build hook mechanism. This allows to ignore remote
|
|||
|
|
builders if they are setup on the machine.</p><p>It's useful in cases where the bandwidth between the client and the
|
|||
|
|
remote builder is too low. In that case it can take more time to upload the
|
|||
|
|
sources to the remote builder and fetch back the result than to do the
|
|||
|
|
computation locally.</p></dd><dt><span class="term"><code class="option">--readonly-mode</code></span></dt><dd><p>When this option is used, no attempt is made to open
|
|||
|
|
the Nix database. Most Nix operations do need database access, so
|
|||
|
|
those operations will fail.</p></dd><dt><span class="term"><code class="option">--arg</code> <em class="replaceable"><code>name</code></em> <em class="replaceable"><code>value</code></em></span></dt><dd><p>This option is accepted by
|
|||
|
|
<span class="command"><strong>nix-env</strong></span>, <span class="command"><strong>nix-instantiate</strong></span>,
|
|||
|
|
<span class="command"><strong>nix-shell</strong></span> and <span class="command"><strong>nix-build</strong></span>.
|
|||
|
|
When evaluating Nix expressions, the expression evaluator will
|
|||
|
|
automatically try to call functions that
|
|||
|
|
it encounters. It can automatically call functions for which every
|
|||
|
|
argument has a <a class="link" href="#ss-functions" title="Functions">default value</a>
|
|||
|
|
(e.g., <code class="literal">{ <em class="replaceable"><code>argName</code></em> ?
|
|||
|
|
<em class="replaceable"><code>defaultValue</code></em> }:
|
|||
|
|
<em class="replaceable"><code>...</code></em></code>). With
|
|||
|
|
<code class="option">--arg</code>, you can also call functions that have
|
|||
|
|
arguments without a default value (or override a default value).
|
|||
|
|
That is, if the evaluator encounters a function with an argument
|
|||
|
|
named <em class="replaceable"><code>name</code></em>, it will call it with value
|
|||
|
|
<em class="replaceable"><code>value</code></em>.</p><p>For instance, the top-level <code class="literal">default.nix</code> in
|
|||
|
|
Nixpkgs is actually a function:
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
{ # The system (e.g., `i686-linux') for which to build the packages.
|
|||
|
|
system ? builtins.currentSystem
|
|||
|
|
<em class="replaceable"><code>...</code></em>
|
|||
|
|
}: <em class="replaceable"><code>...</code></em></pre><p>
|
|||
|
|
|
|||
|
|
So if you call this Nix expression (e.g., when you do
|
|||
|
|
<code class="literal">nix-env -i <em class="replaceable"><code>pkgname</code></em></code>),
|
|||
|
|
the function will be called automatically using the value <a class="link" href="#builtin-currentSystem"><code class="literal">builtins.currentSystem</code></a>
|
|||
|
|
for the <code class="literal">system</code> argument. You can override this
|
|||
|
|
using <code class="option">--arg</code>, e.g., <code class="literal">nix-env -i
|
|||
|
|
<em class="replaceable"><code>pkgname</code></em> --arg system
|
|||
|
|
\"i686-freebsd\"</code>. (Note that since the argument is a Nix
|
|||
|
|
string literal, you have to escape the quotes.)</p></dd><dt><span class="term"><code class="option">--argstr</code> <em class="replaceable"><code>name</code></em> <em class="replaceable"><code>value</code></em></span></dt><dd><p>This option is like <code class="option">--arg</code>, only the
|
|||
|
|
value is not a Nix expression but a string. So instead of
|
|||
|
|
<code class="literal">--arg system \"i686-linux\"</code> (the outer quotes are
|
|||
|
|
to keep the shell happy) you can say <code class="literal">--argstr system
|
|||
|
|
i686-linux</code>.</p></dd><dt><a id="opt-attr"></a><span class="term"><code class="option">--attr</code> / <code class="option">-A</code>
|
|||
|
|
<em class="replaceable"><code>attrPath</code></em></span></dt><dd><p>Select an attribute from the top-level Nix
|
|||
|
|
expression being evaluated. (<span class="command"><strong>nix-env</strong></span>,
|
|||
|
|
<span class="command"><strong>nix-instantiate</strong></span>, <span class="command"><strong>nix-build</strong></span> and
|
|||
|
|
<span class="command"><strong>nix-shell</strong></span> only.) The <span class="emphasis"><em>attribute
|
|||
|
|
path</em></span> <em class="replaceable"><code>attrPath</code></em> is a sequence of
|
|||
|
|
attribute names separated by dots. For instance, given a top-level
|
|||
|
|
Nix expression <em class="replaceable"><code>e</code></em>, the attribute path
|
|||
|
|
<code class="literal">xorg.xorgserver</code> would cause the expression
|
|||
|
|
<code class="literal"><em class="replaceable"><code>e</code></em>.xorg.xorgserver</code> to
|
|||
|
|
be used. See <a class="link" href="#refsec-nix-env-install-examples" title="Examples"><span class="command"><strong>nix-env
|
|||
|
|
--install</strong></span></a> for some concrete examples.</p><p>In addition to attribute names, you can also specify array
|
|||
|
|
indices. For instance, the attribute path
|
|||
|
|
<code class="literal">foo.3.bar</code> selects the <code class="literal">bar</code>
|
|||
|
|
attribute of the fourth element of the array in the
|
|||
|
|
<code class="literal">foo</code> attribute of the top-level
|
|||
|
|
expression.</p></dd><dt><span class="term"><code class="option">--expr</code> / <code class="option">-E</code></span></dt><dd><p>Interpret the command line arguments as a list of
|
|||
|
|
Nix expressions to be parsed and evaluated, rather than as a list
|
|||
|
|
of file names of Nix expressions.
|
|||
|
|
(<span class="command"><strong>nix-instantiate</strong></span>, <span class="command"><strong>nix-build</strong></span>
|
|||
|
|
and <span class="command"><strong>nix-shell</strong></span> only.)</p><p>For <span class="command"><strong>nix-shell</strong></span>, this option is commonly used
|
|||
|
|
to give you a shell in which you can build the packages returned
|
|||
|
|
by the expression. If you want to get a shell which contain the
|
|||
|
|
<span class="emphasis"><em>built</em></span> packages ready for use, give your
|
|||
|
|
expression to the <span class="command"><strong>nix-shell -p</strong></span> convenience flag
|
|||
|
|
instead.</p></dd><dt><a id="opt-I"></a><span class="term"><code class="option">-I</code> <em class="replaceable"><code>path</code></em></span></dt><dd><p>Add a path to the Nix expression search path. This
|
|||
|
|
option may be given multiple times. See the <code class="envar"><a class="envar" href="#env-NIX_PATH">NIX_PATH</a></code> environment variable for
|
|||
|
|
information on the semantics of the Nix search path. Paths added
|
|||
|
|
through <code class="option">-I</code> take precedence over
|
|||
|
|
<code class="envar">NIX_PATH</code>.</p></dd><dt><span class="term"><code class="option">--option</code> <em class="replaceable"><code>name</code></em> <em class="replaceable"><code>value</code></em></span></dt><dd><p>Set the Nix configuration option
|
|||
|
|
<em class="replaceable"><code>name</code></em> to <em class="replaceable"><code>value</code></em>.
|
|||
|
|
This overrides settings in the Nix configuration file (see
|
|||
|
|
<span class="citerefentry"><span class="refentrytitle">nix.conf</span>(5)</span>).</p></dd><dt><span class="term"><code class="option">--repair</code></span></dt><dd><p>Fix corrupted or missing store paths by
|
|||
|
|
redownloading or rebuilding them. Note that this is slow because it
|
|||
|
|
requires computing a cryptographic hash of the contents of every
|
|||
|
|
path in the closure of the build. Also note the warning under
|
|||
|
|
<span class="command"><strong>nix-store --repair-path</strong></span>.</p></dd></dl></div></div><div class="chapter"><div class="titlepage"><div><div><h2 class="title"><a id="sec-common-env"></a>Chapter 21. Common Environment Variables</h2></div></div></div><p>Most Nix commands interpret the following environment variables:</p><div class="variablelist"><a id="env-common"></a><dl class="variablelist"><dt><span class="term"><code class="envar">IN_NIX_SHELL</code></span></dt><dd><p>Indicator that tells if the current environment was set up by
|
|||
|
|
<span class="command"><strong>nix-shell</strong></span>. Since Nix 2.0 the values are
|
|||
|
|
<code class="literal">"pure"</code> and <code class="literal">"impure"</code></p></dd><dt><a id="env-NIX_PATH"></a><span class="term"><code class="envar">NIX_PATH</code></span></dt><dd><p>A colon-separated list of directories used to look up Nix
|
|||
|
|
expressions enclosed in angle brackets (i.e.,
|
|||
|
|
<code class="literal"><<em class="replaceable"><code>path</code></em>></code>). For
|
|||
|
|
instance, the value
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
/home/eelco/Dev:/etc/nixos</pre><p>
|
|||
|
|
|
|||
|
|
will cause Nix to look for paths relative to
|
|||
|
|
<code class="filename">/home/eelco/Dev</code> and
|
|||
|
|
<code class="filename">/etc/nixos</code>, in this order. It is also
|
|||
|
|
possible to match paths against a prefix. For example, the value
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
nixpkgs=/home/eelco/Dev/nixpkgs-branch:/etc/nixos</pre><p>
|
|||
|
|
|
|||
|
|
will cause Nix to search for
|
|||
|
|
<code class="literal"><nixpkgs/<em class="replaceable"><code>path</code></em>></code> in
|
|||
|
|
<code class="filename">/home/eelco/Dev/nixpkgs-branch/<em class="replaceable"><code>path</code></em></code>
|
|||
|
|
and
|
|||
|
|
<code class="filename">/etc/nixos/nixpkgs/<em class="replaceable"><code>path</code></em></code>.</p><p>If a path in the Nix search path starts with
|
|||
|
|
<code class="literal">http://</code> or <code class="literal">https://</code>, it is
|
|||
|
|
interpreted as the URL of a tarball that will be downloaded and
|
|||
|
|
unpacked to a temporary location. The tarball must consist of a
|
|||
|
|
single top-level directory. For example, setting
|
|||
|
|
<code class="envar">NIX_PATH</code> to
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
nixpkgs=https://github.com/NixOS/nixpkgs/archive/nixos-15.09.tar.gz</pre><p>
|
|||
|
|
|
|||
|
|
tells Nix to download the latest revision in the Nixpkgs/NixOS
|
|||
|
|
15.09 channel.</p><p>A following shorthand can be used to refer to the official channels:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">nixpkgs=channel:nixos-15.09</pre><p>
|
|||
|
|
</p><p>The search path can be extended using the <code class="option"><a class="option" href="#opt-I">-I</a></code> option, which takes precedence over
|
|||
|
|
<code class="envar">NIX_PATH</code>.</p></dd><dt><span class="term"><code class="envar">NIX_IGNORE_SYMLINK_STORE</code></span></dt><dd><p>Normally, the Nix store directory (typically
|
|||
|
|
<code class="filename">/nix/store</code>) is not allowed to contain any
|
|||
|
|
symlink components. This is to prevent “impure” builds. Builders
|
|||
|
|
sometimes “canonicalise” paths by resolving all symlink components.
|
|||
|
|
Thus, builds on different machines (with
|
|||
|
|
<code class="filename">/nix/store</code> resolving to different locations)
|
|||
|
|
could yield different results. This is generally not a problem,
|
|||
|
|
except when builds are deployed to machines where
|
|||
|
|
<code class="filename">/nix/store</code> resolves differently. If you are
|
|||
|
|
sure that you’re not going to do that, you can set
|
|||
|
|
<code class="envar">NIX_IGNORE_SYMLINK_STORE</code> to <code class="envar">1</code>.</p><p>Note that if you’re symlinking the Nix store so that you can
|
|||
|
|
put it on another file system than the root file system, on Linux
|
|||
|
|
you’re better off using <code class="literal">bind</code> mount points, e.g.,
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ mkdir /nix
|
|||
|
|
$ mount -o bind /mnt/otherdisk/nix /nix</pre><p>
|
|||
|
|
|
|||
|
|
Consult the <span class="citerefentry"><span class="refentrytitle">mount</span>(8)</span> manual page for details.</p></dd><dt><span class="term"><code class="envar">NIX_STORE_DIR</code></span></dt><dd><p>Overrides the location of the Nix store (default
|
|||
|
|
<code class="filename"><em class="replaceable"><code>prefix</code></em>/store</code>).</p></dd><dt><span class="term"><code class="envar">NIX_DATA_DIR</code></span></dt><dd><p>Overrides the location of the Nix static data
|
|||
|
|
directory (default
|
|||
|
|
<code class="filename"><em class="replaceable"><code>prefix</code></em>/share</code>).</p></dd><dt><span class="term"><code class="envar">NIX_LOG_DIR</code></span></dt><dd><p>Overrides the location of the Nix log directory
|
|||
|
|
(default <code class="filename"><em class="replaceable"><code>prefix</code></em>/var/log/nix</code>).</p></dd><dt><span class="term"><code class="envar">NIX_STATE_DIR</code></span></dt><dd><p>Overrides the location of the Nix state directory
|
|||
|
|
(default <code class="filename"><em class="replaceable"><code>prefix</code></em>/var/nix</code>).</p></dd><dt><span class="term"><code class="envar">NIX_CONF_DIR</code></span></dt><dd><p>Overrides the location of the system Nix configuration
|
|||
|
|
directory (default
|
|||
|
|
<code class="filename"><em class="replaceable"><code>prefix</code></em>/etc/nix</code>).</p></dd><dt><span class="term"><code class="envar">NIX_USER_CONF_FILES</code></span></dt><dd><p>Overrides the location of the user Nix configuration files
|
|||
|
|
to load from (defaults to the XDG spec locations). The variable is treated
|
|||
|
|
as a list separated by the <code class="literal">:</code> token.</p></dd><dt><span class="term"><code class="envar">TMPDIR</code></span></dt><dd><p>Use the specified directory to store temporary
|
|||
|
|
files. In particular, this includes temporary build directories;
|
|||
|
|
these can take up substantial amounts of disk space. The default is
|
|||
|
|
<code class="filename">/tmp</code>.</p></dd><dt><a id="envar-remote"></a><span class="term"><code class="envar">NIX_REMOTE</code></span></dt><dd><p>This variable should be set to
|
|||
|
|
<code class="literal">daemon</code> if you want to use the Nix daemon to
|
|||
|
|
execute Nix operations. This is necessary in <a class="link" href="#ssec-multi-user" title="6.2. Multi-User Mode">multi-user Nix installations</a>.
|
|||
|
|
If the Nix daemon's Unix socket is at some non-standard path,
|
|||
|
|
this variable should be set to <code class="literal">unix://path/to/socket</code>.
|
|||
|
|
Otherwise, it should be left unset.</p></dd><dt><span class="term"><code class="envar">NIX_SHOW_STATS</code></span></dt><dd><p>If set to <code class="literal">1</code>, Nix will print some
|
|||
|
|
evaluation statistics, such as the number of values
|
|||
|
|
allocated.</p></dd><dt><span class="term"><code class="envar">NIX_COUNT_CALLS</code></span></dt><dd><p>If set to <code class="literal">1</code>, Nix will print how
|
|||
|
|
often functions were called during Nix expression evaluation. This
|
|||
|
|
is useful for profiling your Nix expressions.</p></dd><dt><span class="term"><code class="envar">GC_INITIAL_HEAP_SIZE</code></span></dt><dd><p>If Nix has been configured to use the Boehm garbage
|
|||
|
|
collector, this variable sets the initial size of the heap in bytes.
|
|||
|
|
It defaults to 384 MiB. Setting it to a low value reduces memory
|
|||
|
|
consumption, but will increase runtime due to the overhead of
|
|||
|
|
garbage collection.</p></dd></dl></div></div><div class="chapter"><div class="titlepage"><div><div><h2 class="title"><a id="ch-main-commands"></a>Chapter 22. Main Commands</h2></div></div></div><p>This section lists commands and options that you can use when you
|
|||
|
|
work with Nix.</p><div class="refentry"><a id="sec-nix-env"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>nix-env — manipulate or query Nix user environments</p></div><div class="refsynopsisdiv"><h2>Synopsis</h2><div class="cmdsynopsis"><p><code class="command">nix-env</code> [<code class="option">--help</code>] [<code class="option">--version</code>] [
|
|||
|
|
{ <code class="option">--verbose</code> | <code class="option">-v</code> }
|
|||
|
|
...] [
|
|||
|
|
<code class="option">--quiet</code>
|
|||
|
|
] [
|
|||
|
|
<code class="option">--log-format</code>
|
|||
|
|
<em class="replaceable"><code>format</code></em>
|
|||
|
|
] [
|
|||
|
|
<code class="option">--no-build-output</code> | <code class="option">-Q</code>
|
|||
|
|
] [
|
|||
|
|
{ <code class="option">--max-jobs</code> | <code class="option">-j</code> }
|
|||
|
|
<em class="replaceable"><code>number</code></em>
|
|||
|
|
] [
|
|||
|
|
<code class="option">--cores</code>
|
|||
|
|
<em class="replaceable"><code>number</code></em>
|
|||
|
|
] [
|
|||
|
|
<code class="option">--max-silent-time</code>
|
|||
|
|
<em class="replaceable"><code>number</code></em>
|
|||
|
|
] [
|
|||
|
|
<code class="option">--timeout</code>
|
|||
|
|
<em class="replaceable"><code>number</code></em>
|
|||
|
|
] [
|
|||
|
|
<code class="option">--keep-going</code> | <code class="option">-k</code>
|
|||
|
|
] [
|
|||
|
|
<code class="option">--keep-failed</code> | <code class="option">-K</code>
|
|||
|
|
] [<code class="option">--fallback</code>] [<code class="option">--readonly-mode</code>] [
|
|||
|
|
<code class="option">-I</code>
|
|||
|
|
<em class="replaceable"><code>path</code></em>
|
|||
|
|
] [
|
|||
|
|
<code class="option">--option</code>
|
|||
|
|
<em class="replaceable"><code>name</code></em>
|
|||
|
|
<em class="replaceable"><code>value</code></em>
|
|||
|
|
]<br /> [<code class="option">--arg</code> <em class="replaceable"><code>name</code></em> <em class="replaceable"><code>value</code></em>] [<code class="option">--argstr</code> <em class="replaceable"><code>name</code></em> <em class="replaceable"><code>value</code></em>] [
|
|||
|
|
{ <code class="option">--file</code> | <code class="option">-f</code> }
|
|||
|
|
<em class="replaceable"><code>path</code></em>
|
|||
|
|
] [
|
|||
|
|
{ <code class="option">--profile</code> | <code class="option">-p</code> }
|
|||
|
|
<em class="replaceable"><code>path</code></em>
|
|||
|
|
] [
|
|||
|
|
<code class="option">--system-filter</code>
|
|||
|
|
<em class="replaceable"><code>system</code></em>
|
|||
|
|
] [<code class="option">--dry-run</code>] <em class="replaceable"><code>operation</code></em> [<em class="replaceable"><code>options</code></em>...] [<em class="replaceable"><code>arguments</code></em>...]</p></div></div><div class="refsection"><a id="idm139733300260096"></a><h2>Description</h2><p>The command <span class="command"><strong>nix-env</strong></span> is used to manipulate Nix
|
|||
|
|
user environments. User environments are sets of software packages
|
|||
|
|
available to a user at some point in time. In other words, they are a
|
|||
|
|
synthesised view of the programs available in the Nix store. There
|
|||
|
|
may be many user environments: different users can have different
|
|||
|
|
environments, and individual users can switch between different
|
|||
|
|
environments.</p><p><span class="command"><strong>nix-env</strong></span> takes exactly one
|
|||
|
|
<span class="emphasis"><em>operation</em></span> flag which indicates the subcommand to
|
|||
|
|
be performed. These are documented below.</p></div><div class="refsection"><a id="idm139733300256528"></a><h2>Selectors</h2><p>Several commands, such as <span class="command"><strong>nix-env -q</strong></span> and
|
|||
|
|
<span class="command"><strong>nix-env -i</strong></span>, take a list of arguments that specify
|
|||
|
|
the packages on which to operate. These are extended regular
|
|||
|
|
expressions that must match the entire name of the package. (For
|
|||
|
|
details on regular expressions, see
|
|||
|
|
<span class="citerefentry"><span class="refentrytitle">regex</span>(7)</span>.)
|
|||
|
|
The match is case-sensitive. The regular expression can optionally be
|
|||
|
|
followed by a dash and a version number; if omitted, any version of
|
|||
|
|
the package will match. Here are some examples:
|
|||
|
|
|
|||
|
|
</p><div class="variablelist"><dl class="variablelist"><dt><span class="term"><code class="literal">firefox</code></span></dt><dd><p>Matches the package name
|
|||
|
|
<code class="literal">firefox</code> and any version.</p></dd><dt><span class="term"><code class="literal">firefox-32.0</code></span></dt><dd><p>Matches the package name
|
|||
|
|
<code class="literal">firefox</code> and version
|
|||
|
|
<code class="literal">32.0</code>.</p></dd><dt><span class="term"><code class="literal">gtk\\+</code></span></dt><dd><p>Matches the package name
|
|||
|
|
<code class="literal">gtk+</code>. The <code class="literal">+</code> character must
|
|||
|
|
be escaped using a backslash to prevent it from being interpreted
|
|||
|
|
as a quantifier, and the backslash must be escaped in turn with
|
|||
|
|
another backslash to ensure that the shell passes it
|
|||
|
|
on.</p></dd><dt><span class="term"><code class="literal">.\*</code></span></dt><dd><p>Matches any package name. This is the default for
|
|||
|
|
most commands.</p></dd><dt><span class="term"><code class="literal">'.*zip.*'</code></span></dt><dd><p>Matches any package name containing the string
|
|||
|
|
<code class="literal">zip</code>. Note the dots: <code class="literal">'*zip*'</code>
|
|||
|
|
does not work, because in a regular expression, the character
|
|||
|
|
<code class="literal">*</code> is interpreted as a
|
|||
|
|
quantifier.</p></dd><dt><span class="term"><code class="literal">'.*(firefox|chromium).*'</code></span></dt><dd><p>Matches any package name containing the strings
|
|||
|
|
<code class="literal">firefox</code> or
|
|||
|
|
<code class="literal">chromium</code>.</p></dd></dl></div><p>
|
|||
|
|
|
|||
|
|
</p></div><div class="refsection"><a id="idm139733300238960"></a><h2>Common options</h2><p>This section lists the options that are common to all
|
|||
|
|
operations. These options are allowed for every subcommand, though
|
|||
|
|
they may not always have an effect. <span class="phrase">See
|
|||
|
|
also <a class="xref" href="#sec-common-options" title="Chapter 20. Common Options">Chapter 20, <em>Common Options</em></a>.</span></p><div class="variablelist"><dl class="variablelist"><dt><span class="term"><code class="option">--file</code> / <code class="option">-f</code> <em class="replaceable"><code>path</code></em></span></dt><dd><p>Specifies the Nix expression (designated below as
|
|||
|
|
the <span class="emphasis"><em>active Nix expression</em></span>) used by the
|
|||
|
|
<code class="option">--install</code>, <code class="option">--upgrade</code>, and
|
|||
|
|
<code class="option">--query --available</code> operations to obtain
|
|||
|
|
derivations. The default is
|
|||
|
|
<code class="filename">~/.nix-defexpr</code>.</p><p>If the argument starts with <code class="literal">http://</code> or
|
|||
|
|
<code class="literal">https://</code>, it is interpreted as the URL of a
|
|||
|
|
tarball that will be downloaded and unpacked to a temporary
|
|||
|
|
location. The tarball must include a single top-level directory
|
|||
|
|
containing at least a file named <code class="filename">default.nix</code>.</p></dd><dt><span class="term"><code class="option">--profile</code> / <code class="option">-p</code> <em class="replaceable"><code>path</code></em></span></dt><dd><p>Specifies the profile to be used by those
|
|||
|
|
operations that operate on a profile (designated below as the
|
|||
|
|
<span class="emphasis"><em>active profile</em></span>). A profile is a sequence of
|
|||
|
|
user environments called <span class="emphasis"><em>generations</em></span>, one of
|
|||
|
|
which is the <span class="emphasis"><em>current
|
|||
|
|
generation</em></span>.</p></dd><dt><span class="term"><code class="option">--dry-run</code></span></dt><dd><p>For the <code class="option">--install</code>,
|
|||
|
|
<code class="option">--upgrade</code>, <code class="option">--uninstall</code>,
|
|||
|
|
<code class="option">--switch-generation</code>,
|
|||
|
|
<code class="option">--delete-generations</code> and
|
|||
|
|
<code class="option">--rollback</code> operations, this flag will cause
|
|||
|
|
<span class="command"><strong>nix-env</strong></span> to print what
|
|||
|
|
<span class="emphasis"><em>would</em></span> be done if this flag had not been
|
|||
|
|
specified, without actually doing it.</p><p><code class="option">--dry-run</code> also prints out which paths will
|
|||
|
|
be <a class="link" href="#gloss-substitute" title="substitute">substituted</a> (i.e.,
|
|||
|
|
downloaded) and which paths will be built from source (because no
|
|||
|
|
substitute is available).</p></dd><dt><span class="term"><code class="option">--system-filter</code> <em class="replaceable"><code>system</code></em></span></dt><dd><p>By default, operations such as <code class="option">--query
|
|||
|
|
--available</code> show derivations matching any platform. This
|
|||
|
|
option allows you to use derivations for the specified platform
|
|||
|
|
<em class="replaceable"><code>system</code></em>.</p></dd></dl></div></div><div class="refsection"><a id="idm139733300216432"></a><h2>Files</h2><div class="variablelist"><dl class="variablelist"><dt><span class="term"><code class="filename">~/.nix-defexpr</code></span></dt><dd><p>The source for the default Nix
|
|||
|
|
expressions used by the <code class="option">--install</code>,
|
|||
|
|
<code class="option">--upgrade</code>, and <code class="option">--query
|
|||
|
|
--available</code> operations to obtain derivations. The
|
|||
|
|
<code class="option">--file</code> option may be used to override this
|
|||
|
|
default.</p><p>If <code class="filename">~/.nix-defexpr</code> is a file,
|
|||
|
|
it is loaded as a Nix expression. If the expression
|
|||
|
|
is a set, it is used as the default Nix expression.
|
|||
|
|
If the expression is a function, an empty set is passed
|
|||
|
|
as argument and the return value is used as
|
|||
|
|
the default Nix expression.</p><p>If <code class="filename">~/.nix-defexpr</code> is a directory
|
|||
|
|
containing a <code class="filename">default.nix</code> file, that file
|
|||
|
|
is loaded as in the above paragraph.</p><p>If <code class="filename">~/.nix-defexpr</code> is a directory without
|
|||
|
|
a <code class="filename">default.nix</code> file, then its contents
|
|||
|
|
(both files and subdirectories) are loaded as Nix expressions.
|
|||
|
|
The expressions are combined into a single set, each expression
|
|||
|
|
under an attribute with the same name as the original file
|
|||
|
|
or subdirectory.
|
|||
|
|
</p><p>For example, if <code class="filename">~/.nix-defexpr</code> contains
|
|||
|
|
two files, <code class="filename">foo.nix</code> and <code class="filename">bar.nix</code>,
|
|||
|
|
then the default Nix expression will essentially be
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
{
|
|||
|
|
foo = import ~/.nix-defexpr/foo.nix;
|
|||
|
|
bar = import ~/.nix-defexpr/bar.nix;
|
|||
|
|
}</pre><p>
|
|||
|
|
|
|||
|
|
</p><p>The file <code class="filename">manifest.nix</code> is always ignored.
|
|||
|
|
Subdirectories without a <code class="filename">default.nix</code> file
|
|||
|
|
are traversed recursively in search of more Nix expressions,
|
|||
|
|
but the names of these intermediate directories are not
|
|||
|
|
added to the attribute paths of the default Nix expression.</p><p>The command <span class="command"><strong>nix-channel</strong></span> places symlinks
|
|||
|
|
to the downloaded Nix expressions from each subscribed channel in
|
|||
|
|
this directory.</p></dd><dt><span class="term"><code class="filename">~/.nix-profile</code></span></dt><dd><p>A symbolic link to the user's current profile. By
|
|||
|
|
default, this symlink points to
|
|||
|
|
<code class="filename"><em class="replaceable"><code>prefix</code></em>/var/nix/profiles/default</code>.
|
|||
|
|
The <code class="envar">PATH</code> environment variable should include
|
|||
|
|
<code class="filename">~/.nix-profile/bin</code> for the user environment
|
|||
|
|
to be visible to the user.</p></dd></dl></div></div><div class="refsection"><a id="rsec-nix-env-install"></a><h2>Operation <code class="option">--install</code></h2><div class="refsection"><a id="idm139733300198432"></a><h3>Synopsis</h3><div class="cmdsynopsis"><p><code class="command">nix-env</code> { <code class="option">--install</code> | <code class="option">-i</code> } [
|
|||
|
|
{ <code class="option">--prebuilt-only</code> | <code class="option">-b</code> }
|
|||
|
|
] [
|
|||
|
|
{ <code class="option">--attr</code> | <code class="option">-A</code> }
|
|||
|
|
] [<code class="option">--from-expression</code>] [<code class="option">-E</code>] [<code class="option">--from-profile</code> <em class="replaceable"><code>path</code></em>] [ <code class="option">--preserve-installed</code> | <code class="option">-P</code> ] [ <code class="option">--remove-all</code> | <code class="option">-r</code> ] <em class="replaceable"><code>args</code></em>... </p></div></div><div class="refsection"><a id="idm139733300182432"></a><h3>Description</h3><p>The install operation creates a new user environment, based on
|
|||
|
|
the current generation of the active profile, to which a set of store
|
|||
|
|
paths described by <em class="replaceable"><code>args</code></em> is added. The
|
|||
|
|
arguments <em class="replaceable"><code>args</code></em> map to store paths in a
|
|||
|
|
number of possible ways:
|
|||
|
|
|
|||
|
|
</p><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><p>By default, <em class="replaceable"><code>args</code></em> is a set
|
|||
|
|
of derivation names denoting derivations in the active Nix
|
|||
|
|
expression. These are realised, and the resulting output paths are
|
|||
|
|
installed. Currently installed derivations with a name equal to the
|
|||
|
|
name of a derivation being added are removed unless the option
|
|||
|
|
<code class="option">--preserve-installed</code> is
|
|||
|
|
specified.</p><p>If there are multiple derivations matching a name in
|
|||
|
|
<em class="replaceable"><code>args</code></em> that have the same name (e.g.,
|
|||
|
|
<code class="literal">gcc-3.3.6</code> and <code class="literal">gcc-4.1.1</code>), then
|
|||
|
|
the derivation with the highest <span class="emphasis"><em>priority</em></span> is
|
|||
|
|
used. A derivation can define a priority by declaring the
|
|||
|
|
<code class="varname">meta.priority</code> attribute. This attribute should
|
|||
|
|
be a number, with a higher value denoting a lower priority. The
|
|||
|
|
default priority is <code class="literal">0</code>.</p><p>If there are multiple matching derivations with the same
|
|||
|
|
priority, then the derivation with the highest version will be
|
|||
|
|
installed.</p><p>You can force the installation of multiple derivations with
|
|||
|
|
the same name by being specific about the versions. For instance,
|
|||
|
|
<code class="literal">nix-env -i gcc-3.3.6 gcc-4.1.1</code> will install both
|
|||
|
|
version of GCC (and will probably cause a user environment
|
|||
|
|
conflict!).</p></li><li class="listitem"><p>If <a class="link" href="#opt-attr"><code class="option">--attr</code></a>
|
|||
|
|
(<code class="option">-A</code>) is specified, the arguments are
|
|||
|
|
<span class="emphasis"><em>attribute paths</em></span> that select attributes from the
|
|||
|
|
top-level Nix expression. This is faster than using derivation
|
|||
|
|
names and unambiguous. To find out the attribute paths of available
|
|||
|
|
packages, use <code class="literal">nix-env -qaP</code>.</p></li><li class="listitem"><p>If <code class="option">--from-profile</code>
|
|||
|
|
<em class="replaceable"><code>path</code></em> is given,
|
|||
|
|
<em class="replaceable"><code>args</code></em> is a set of names denoting installed
|
|||
|
|
store paths in the profile <em class="replaceable"><code>path</code></em>. This is
|
|||
|
|
an easy way to copy user environment elements from one profile to
|
|||
|
|
another.</p></li><li class="listitem"><p>If <code class="option">--from-expression</code> is given,
|
|||
|
|
<em class="replaceable"><code>args</code></em> are Nix <a class="link" href="#ss-functions" title="Functions">functions</a> that are called with the
|
|||
|
|
active Nix expression as their single argument. The derivations
|
|||
|
|
returned by those function calls are installed. This allows
|
|||
|
|
derivations to be specified in an unambiguous way, which is necessary
|
|||
|
|
if there are multiple derivations with the same
|
|||
|
|
name.</p></li><li class="listitem"><p>If <em class="replaceable"><code>args</code></em> are store
|
|||
|
|
derivations, then these are <a class="link" href="#rsec-nix-store-realise" title="Operation --realise">realised</a>, and the resulting
|
|||
|
|
output paths are installed.</p></li><li class="listitem"><p>If <em class="replaceable"><code>args</code></em> are store paths
|
|||
|
|
that are not store derivations, then these are <a class="link" href="#rsec-nix-store-realise" title="Operation --realise">realised</a> and
|
|||
|
|
installed.</p></li><li class="listitem"><p>By default all outputs are installed for each derivation.
|
|||
|
|
That can be reduced by setting <code class="literal">meta.outputsToInstall</code>.
|
|||
|
|
</p></li></ul></div><p>
|
|||
|
|
|
|||
|
|
</p></div><div class="refsection"><a id="idm139733300160752"></a><h3>Flags</h3><div class="variablelist"><dl class="variablelist"><dt><span class="term"><code class="option">--prebuilt-only</code> / <code class="option">-b</code></span></dt><dd><p>Use only derivations for which a substitute is
|
|||
|
|
registered, i.e., there is a pre-built binary available that can
|
|||
|
|
be downloaded in lieu of building the derivation. Thus, no
|
|||
|
|
packages will be built from source.</p></dd><dt><span class="term"><code class="option">--preserve-installed</code>, </span><span class="term"><code class="option">-P</code></span></dt><dd><p>Do not remove derivations with a name matching one
|
|||
|
|
of the derivations being installed. Usually, trying to have two
|
|||
|
|
versions of the same package installed in the same generation of a
|
|||
|
|
profile will lead to an error in building the generation, due to
|
|||
|
|
file name clashes between the two versions. However, this is not
|
|||
|
|
the case for all packages.</p></dd><dt><span class="term"><code class="option">--remove-all</code>, </span><span class="term"><code class="option">-r</code></span></dt><dd><p>Remove all previously installed packages first.
|
|||
|
|
This is equivalent to running <code class="literal">nix-env -e '.*'</code>
|
|||
|
|
first, except that everything happens in a single
|
|||
|
|
transaction.</p></dd></dl></div></div><div class="refsection"><a id="refsec-nix-env-install-examples"></a><h3>Examples</h3><p>To install a specific version of <span class="command"><strong>gcc</strong></span> from the
|
|||
|
|
active Nix expression:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-env --install gcc-3.3.2
|
|||
|
|
installing `gcc-3.3.2'
|
|||
|
|
uninstalling `gcc-3.1'</pre><p>
|
|||
|
|
|
|||
|
|
Note the previously installed version is removed, since
|
|||
|
|
<code class="option">--preserve-installed</code> was not specified.</p><p>To install an arbitrary version:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-env --install gcc
|
|||
|
|
installing `gcc-3.3.2'</pre><p>
|
|||
|
|
|
|||
|
|
</p><p>To install using a specific attribute:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-env -i -A gcc40mips
|
|||
|
|
$ nix-env -i -A xorg.xorgserver</pre><p>
|
|||
|
|
|
|||
|
|
</p><p>To install all derivations in the Nix expression <code class="filename">foo.nix</code>:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-env -f ~/foo.nix -i '.*'</pre><p>
|
|||
|
|
|
|||
|
|
</p><p>To copy the store path with symbolic name <code class="literal">gcc</code>
|
|||
|
|
from another profile:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-env -i --from-profile /nix/var/nix/profiles/foo gcc</pre><p>
|
|||
|
|
|
|||
|
|
</p><p>To install a specific store derivation (typically created by
|
|||
|
|
<span class="command"><strong>nix-instantiate</strong></span>):
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-env -i /nix/store/fibjb1bfbpm5mrsxc4mh2d8n37sxh91i-gcc-3.4.3.drv</pre><p>
|
|||
|
|
|
|||
|
|
</p><p>To install a specific output path:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-env -i /nix/store/y3cgx0xj1p4iv9x0pnnmdhr8iyg741vk-gcc-3.4.3</pre><p>
|
|||
|
|
|
|||
|
|
</p><p>To install from a Nix expression specified on the command-line:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-env -f ./foo.nix -i -E \
|
|||
|
|
'f: (f {system = "i686-linux";}).subversionWithJava'</pre><p>
|
|||
|
|
|
|||
|
|
I.e., this evaluates to <code class="literal">(f: (f {system =
|
|||
|
|
"i686-linux";}).subversionWithJava) (import ./foo.nix)</code>, thus
|
|||
|
|
selecting the <code class="literal">subversionWithJava</code> attribute from the
|
|||
|
|
set returned by calling the function defined in
|
|||
|
|
<code class="filename">./foo.nix</code>.</p><p>A dry-run tells you which paths will be downloaded or built from
|
|||
|
|
source:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-env -f '<nixpkgs>' -iA hello --dry-run
|
|||
|
|
(dry run; not doing anything)
|
|||
|
|
installing ‘hello-2.10’
|
|||
|
|
this path will be fetched (0.04 MiB download, 0.19 MiB unpacked):
|
|||
|
|
/nix/store/wkhdf9jinag5750mqlax6z2zbwhqb76n-hello-2.10
|
|||
|
|
<em class="replaceable"><code>...</code></em></pre><p>
|
|||
|
|
|
|||
|
|
</p><p>To install Firefox from the latest revision in the Nixpkgs/NixOS
|
|||
|
|
14.12 channel:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-env -f https://github.com/NixOS/nixpkgs/archive/nixos-14.12.tar.gz -iA firefox
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
</p></div></div><div class="refsection"><a id="rsec-nix-env-upgrade"></a><h2>Operation <code class="option">--upgrade</code></h2><div class="refsection"><a id="idm139733300136496"></a><h3>Synopsis</h3><div class="cmdsynopsis"><p><code class="command">nix-env</code> { <code class="option">--upgrade</code> | <code class="option">-u</code> } [
|
|||
|
|
{ <code class="option">--prebuilt-only</code> | <code class="option">-b</code> }
|
|||
|
|
] [
|
|||
|
|
{ <code class="option">--attr</code> | <code class="option">-A</code> }
|
|||
|
|
] [<code class="option">--from-expression</code>] [<code class="option">-E</code>] [<code class="option">--from-profile</code> <em class="replaceable"><code>path</code></em>] [ <code class="option">--lt</code> | <code class="option">--leq</code> | <code class="option">--eq</code> | <code class="option">--always</code> ] <em class="replaceable"><code>args</code></em>... </p></div></div><div class="refsection"><a id="idm139733300121104"></a><h3>Description</h3><p>The upgrade operation creates a new user environment, based on
|
|||
|
|
the current generation of the active profile, in which all store paths
|
|||
|
|
are replaced for which there are newer versions in the set of paths
|
|||
|
|
described by <em class="replaceable"><code>args</code></em>. Paths for which there
|
|||
|
|
are no newer versions are left untouched; this is not an error. It is
|
|||
|
|
also not an error if an element of <em class="replaceable"><code>args</code></em>
|
|||
|
|
matches no installed derivations.</p><p>For a description of how <em class="replaceable"><code>args</code></em> is
|
|||
|
|
mapped to a set of store paths, see <a class="link" href="#rsec-nix-env-install" title="Operation --install"><code class="option">--install</code></a>. If
|
|||
|
|
<em class="replaceable"><code>args</code></em> describes multiple store paths with
|
|||
|
|
the same symbolic name, only the one with the highest version is
|
|||
|
|
installed.</p></div><div class="refsection"><a id="idm139733300116496"></a><h3>Flags</h3><div class="variablelist"><dl class="variablelist"><dt><span class="term"><code class="option">--lt</code></span></dt><dd><p>Only upgrade a derivation to newer versions. This
|
|||
|
|
is the default.</p></dd><dt><span class="term"><code class="option">--leq</code></span></dt><dd><p>In addition to upgrading to newer versions, also
|
|||
|
|
“upgrade” to derivations that have the same version. Version are
|
|||
|
|
not a unique identification of a derivation, so there may be many
|
|||
|
|
derivations that have the same version. This flag may be useful
|
|||
|
|
to force “synchronisation” between the installed and available
|
|||
|
|
derivations.</p></dd><dt><span class="term"><code class="option">--eq</code></span></dt><dd><p><span class="emphasis"><em>Only</em></span> “upgrade” to derivations
|
|||
|
|
that have the same version. This may not seem very useful, but it
|
|||
|
|
actually is, e.g., when there is a new release of Nixpkgs and you
|
|||
|
|
want to replace installed applications with the same versions
|
|||
|
|
built against newer dependencies (to reduce the number of
|
|||
|
|
dependencies floating around on your system).</p></dd><dt><span class="term"><code class="option">--always</code></span></dt><dd><p>In addition to upgrading to newer versions, also
|
|||
|
|
“upgrade” to derivations that have the same or a lower version.
|
|||
|
|
I.e., derivations may actually be downgraded depending on what is
|
|||
|
|
available in the active Nix expression.</p></dd></dl></div><p>For the other flags, see <code class="option"><a class="option" href="#rsec-nix-env-install" title="Operation --install">--install</a></code>.</p></div><div class="refsection"><a id="idm139733300106960"></a><h3>Examples</h3><pre class="screen">
|
|||
|
|
$ nix-env --upgrade gcc
|
|||
|
|
upgrading `gcc-3.3.1' to `gcc-3.4'
|
|||
|
|
|
|||
|
|
$ nix-env -u gcc-3.3.2 --always <em class="lineannotation"><span class="lineannotation">(switch to a specific version)</span></em>
|
|||
|
|
upgrading `gcc-3.4' to `gcc-3.3.2'
|
|||
|
|
|
|||
|
|
$ nix-env --upgrade pan
|
|||
|
|
<em class="lineannotation"><span class="lineannotation">(no upgrades available, so nothing happens)</span></em>
|
|||
|
|
|
|||
|
|
$ nix-env -u <em class="lineannotation"><span class="lineannotation">(try to upgrade everything)</span></em>
|
|||
|
|
upgrading `hello-2.1.2' to `hello-2.1.3'
|
|||
|
|
upgrading `mozilla-1.2' to `mozilla-1.4'</pre></div><div class="refsection"><a id="ssec-version-comparisons"></a><h3>Versions</h3><p>The upgrade operation determines whether a derivation
|
|||
|
|
<code class="varname">y</code> is an upgrade of a derivation
|
|||
|
|
<code class="varname">x</code> by looking at their respective
|
|||
|
|
<code class="literal">name</code> attributes. The names (e.g.,
|
|||
|
|
<code class="literal">gcc-3.3.1</code> are split into two parts: the package
|
|||
|
|
name (<code class="literal">gcc</code>), and the version
|
|||
|
|
(<code class="literal">3.3.1</code>). The version part starts after the first
|
|||
|
|
dash not followed by a letter. <code class="varname">x</code> is considered an
|
|||
|
|
upgrade of <code class="varname">y</code> if their package names match, and the
|
|||
|
|
version of <code class="varname">y</code> is higher that that of
|
|||
|
|
<code class="varname">x</code>.</p><p>The versions are compared by splitting them into contiguous
|
|||
|
|
components of numbers and letters. E.g., <code class="literal">3.3.1pre5</code>
|
|||
|
|
is split into <code class="literal">[3, 3, 1, "pre", 5]</code>. These lists are
|
|||
|
|
then compared lexicographically (from left to right). Corresponding
|
|||
|
|
components <code class="varname">a</code> and <code class="varname">b</code> are compared
|
|||
|
|
as follows. If they are both numbers, integer comparison is used. If
|
|||
|
|
<code class="varname">a</code> is an empty string and <code class="varname">b</code> is a
|
|||
|
|
number, <code class="varname">a</code> is considered less than
|
|||
|
|
<code class="varname">b</code>. The special string component
|
|||
|
|
<code class="literal">pre</code> (for <span class="emphasis"><em>pre-release</em></span>) is
|
|||
|
|
considered to be less than other components. String components are
|
|||
|
|
considered less than number components. Otherwise, they are compared
|
|||
|
|
lexicographically (i.e., using case-sensitive string comparison).</p><p>This is illustrated by the following examples:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
1.0 < 2.3
|
|||
|
|
2.1 < 2.3
|
|||
|
|
2.3 = 2.3
|
|||
|
|
2.5 > 2.3
|
|||
|
|
3.1 > 2.3
|
|||
|
|
2.3.1 > 2.3
|
|||
|
|
2.3.1 > 2.3a
|
|||
|
|
2.3pre1 < 2.3
|
|||
|
|
2.3pre3 < 2.3pre12
|
|||
|
|
2.3a < 2.3c
|
|||
|
|
2.3pre1 < 2.3c
|
|||
|
|
2.3pre1 < 2.3q</pre><p>
|
|||
|
|
|
|||
|
|
</p></div></div><div class="refsection"><a id="idm139733300091392"></a><h2>Operation <code class="option">--uninstall</code></h2><div class="refsection"><a id="idm139733300090560"></a><h3>Synopsis</h3><div class="cmdsynopsis"><p><code class="command">nix-env</code> { <code class="option">--uninstall</code> | <code class="option">-e</code> } <em class="replaceable"><code>drvnames</code></em>... </p></div></div><div class="refsection"><a id="idm139733300085776"></a><h3>Description</h3><p>The uninstall operation creates a new user environment, based on
|
|||
|
|
the current generation of the active profile, from which the store
|
|||
|
|
paths designated by the symbolic names
|
|||
|
|
<em class="replaceable"><code>names</code></em> are removed.</p></div><div class="refsection"><a id="idm139733300084080"></a><h3>Examples</h3><pre class="screen">
|
|||
|
|
$ nix-env --uninstall gcc
|
|||
|
|
$ nix-env -e '.*' <em class="lineannotation"><span class="lineannotation">(remove everything)</span></em></pre></div></div><div class="refsection"><a id="rsec-nix-env-set"></a><h2>Operation <code class="option">--set</code></h2><div class="refsection"><a id="idm139733300080928"></a><h3>Synopsis</h3><div class="cmdsynopsis"><p><code class="command">nix-env</code> <code class="option">--set</code> <em class="replaceable"><code>drvname</code></em> </p></div></div><div class="refsection"><a id="idm139733300077824"></a><h3>Description</h3><p>The <code class="option">--set</code> operation modifies the current generation of a
|
|||
|
|
profile so that it contains exactly the specified derivation, and nothing else.
|
|||
|
|
</p></div><div class="refsection"><a id="idm139733300076176"></a><h3>Examples</h3><p>
|
|||
|
|
The following updates a profile such that its current generation will contain
|
|||
|
|
just Firefox:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-env -p /nix/var/nix/profiles/browser --set firefox</pre><p>
|
|||
|
|
|
|||
|
|
</p></div></div><div class="refsection"><a id="rsec-nix-env-set-flag"></a><h2>Operation <code class="option">--set-flag</code></h2><div class="refsection"><a id="idm139733300072736"></a><h3>Synopsis</h3><div class="cmdsynopsis"><p><code class="command">nix-env</code> <code class="option">--set-flag</code> <em class="replaceable"><code>name</code></em> <em class="replaceable"><code>value</code></em> <em class="replaceable"><code>drvnames</code></em>... </p></div></div><div class="refsection"><a id="idm139733300067728"></a><h3>Description</h3><p>The <code class="option">--set-flag</code> operation allows meta attributes
|
|||
|
|
of installed packages to be modified. There are several attributes
|
|||
|
|
that can be usefully modified, because they affect the behaviour of
|
|||
|
|
<span class="command"><strong>nix-env</strong></span> or the user environment build
|
|||
|
|
script:
|
|||
|
|
|
|||
|
|
</p><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><p><code class="varname">priority</code> can be changed to
|
|||
|
|
resolve filename clashes. The user environment build script uses
|
|||
|
|
the <code class="varname">meta.priority</code> attribute of derivations to
|
|||
|
|
resolve filename collisions between packages. Lower priority values
|
|||
|
|
denote a higher priority. For instance, the GCC wrapper package and
|
|||
|
|
the Binutils package in Nixpkgs both have a file
|
|||
|
|
<code class="filename">bin/ld</code>, so previously if you tried to install
|
|||
|
|
both you would get a collision. Now, on the other hand, the GCC
|
|||
|
|
wrapper declares a higher priority than Binutils, so the former’s
|
|||
|
|
<code class="filename">bin/ld</code> is symlinked in the user
|
|||
|
|
environment.</p></li><li class="listitem"><p><code class="varname">keep</code> can be set to
|
|||
|
|
<code class="literal">true</code> to prevent the package from being upgraded
|
|||
|
|
or replaced. This is useful if you want to hang on to an older
|
|||
|
|
version of a package.</p></li><li class="listitem"><p><code class="varname">active</code> can be set to
|
|||
|
|
<code class="literal">false</code> to “disable” the package. That is, no
|
|||
|
|
symlinks will be generated to the files of the package, but it
|
|||
|
|
remains part of the profile (so it won’t be garbage-collected). It
|
|||
|
|
can be set back to <code class="literal">true</code> to re-enable the
|
|||
|
|
package.</p></li></ul></div><p>
|
|||
|
|
|
|||
|
|
</p></div><div class="refsection"><a id="idm139733300058816"></a><h3>Examples</h3><p>To prevent the currently installed Firefox from being upgraded:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-env --set-flag keep true firefox</pre><p>
|
|||
|
|
|
|||
|
|
After this, <span class="command"><strong>nix-env -u</strong></span> will ignore Firefox.</p><p>To disable the currently installed Firefox, then install a new
|
|||
|
|
Firefox while the old remains part of the profile:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-env -q
|
|||
|
|
firefox-2.0.0.9 <em class="lineannotation"><span class="lineannotation">(the current one)</span></em>
|
|||
|
|
|
|||
|
|
$ nix-env --preserve-installed -i firefox-2.0.0.11
|
|||
|
|
installing `firefox-2.0.0.11'
|
|||
|
|
building path(s) `/nix/store/myy0y59q3ig70dgq37jqwg1j0rsapzsl-user-environment'
|
|||
|
|
collision between `/nix/store/<em class="replaceable"><code>...</code></em>-firefox-2.0.0.11/bin/firefox'
|
|||
|
|
and `/nix/store/<em class="replaceable"><code>...</code></em>-firefox-2.0.0.9/bin/firefox'.
|
|||
|
|
<em class="lineannotation"><span class="lineannotation">(i.e., can’t have two active at the same time)</span></em>
|
|||
|
|
|
|||
|
|
$ nix-env --set-flag active false firefox
|
|||
|
|
setting flag on `firefox-2.0.0.9'
|
|||
|
|
|
|||
|
|
$ nix-env --preserve-installed -i firefox-2.0.0.11
|
|||
|
|
installing `firefox-2.0.0.11'
|
|||
|
|
|
|||
|
|
$ nix-env -q
|
|||
|
|
firefox-2.0.0.11 <em class="lineannotation"><span class="lineannotation">(the enabled one)</span></em>
|
|||
|
|
firefox-2.0.0.9 <em class="lineannotation"><span class="lineannotation">(the disabled one)</span></em></pre><p>
|
|||
|
|
|
|||
|
|
</p><p>To make files from <code class="literal">binutils</code> take precedence
|
|||
|
|
over files from <code class="literal">gcc</code>:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-env --set-flag priority 5 binutils
|
|||
|
|
$ nix-env --set-flag priority 10 gcc</pre><p>
|
|||
|
|
|
|||
|
|
</p></div></div><div class="refsection"><a id="idm139733300050640"></a><h2>Operation <code class="option">--query</code></h2><div class="refsection"><a id="idm139733300049808"></a><h3>Synopsis</h3><div class="cmdsynopsis"><p><code class="command">nix-env</code> { <code class="option">--query</code> | <code class="option">-q</code> } [ <code class="option">--installed</code> | <code class="option">--available</code> | <code class="option">-a</code> ]<br /> [
|
|||
|
|
{ <code class="option">--status</code> | <code class="option">-s</code> }
|
|||
|
|
] [
|
|||
|
|
{ <code class="option">--attr-path</code> | <code class="option">-P</code> }
|
|||
|
|
] [<code class="option">--no-name</code>] [
|
|||
|
|
{ <code class="option">--compare-versions</code> | <code class="option">-c</code> }
|
|||
|
|
] [<code class="option">--system</code>] [<code class="option">--drv-path</code>] [<code class="option">--out-path</code>] [<code class="option">--description</code>] [<code class="option">--meta</code>]<br /> [<code class="option">--xml</code>] [<code class="option">--json</code>] [
|
|||
|
|
{ <code class="option">--prebuilt-only</code> | <code class="option">-b</code> }
|
|||
|
|
] [
|
|||
|
|
{ <code class="option">--attr</code> | <code class="option">-A</code> }
|
|||
|
|
<em class="replaceable"><code>attribute-path</code></em>
|
|||
|
|
]<br /> <em class="replaceable"><code>names</code></em>... </p></div></div><div class="refsection"><a id="idm139733300023312"></a><h3>Description</h3><p>The query operation displays information about either the store
|
|||
|
|
paths that are installed in the current generation of the active
|
|||
|
|
profile (<code class="option">--installed</code>), or the derivations that are
|
|||
|
|
available for installation in the active Nix expression
|
|||
|
|
(<code class="option">--available</code>). It only prints information about
|
|||
|
|
derivations whose symbolic name matches one of
|
|||
|
|
<em class="replaceable"><code>names</code></em>.</p><p>The derivations are sorted by their <code class="literal">name</code>
|
|||
|
|
attributes.</p></div><div class="refsection"><a id="idm139733300019760"></a><h3>Source selection</h3><p>The following flags specify the set of things on which the query
|
|||
|
|
operates.</p><div class="variablelist"><dl class="variablelist"><dt><span class="term"><code class="option">--installed</code></span></dt><dd><p>The query operates on the store paths that are
|
|||
|
|
installed in the current generation of the active profile. This
|
|||
|
|
is the default.</p></dd><dt><span class="term"><code class="option">--available</code>, </span><span class="term"><code class="option">-a</code></span></dt><dd><p>The query operates on the derivations that are
|
|||
|
|
available in the active Nix expression.</p></dd></dl></div></div><div class="refsection"><a id="idm139733300014832"></a><h3>Queries</h3><p>The following flags specify what information to display about
|
|||
|
|
the selected derivations. Multiple flags may be specified, in which
|
|||
|
|
case the information is shown in the order given here. Note that the
|
|||
|
|
name of the derivation is shown unless <code class="option">--no-name</code> is
|
|||
|
|
specified.</p><div class="variablelist"><dl class="variablelist"><dt><span class="term"><code class="option">--xml</code></span></dt><dd><p>Print the result in an XML representation suitable
|
|||
|
|
for automatic processing by other tools. The root element is
|
|||
|
|
called <code class="literal">items</code>, which contains a
|
|||
|
|
<code class="literal">item</code> element for each available or installed
|
|||
|
|
derivation. The fields discussed below are all stored in
|
|||
|
|
attributes of the <code class="literal">item</code>
|
|||
|
|
elements.</p></dd><dt><span class="term"><code class="option">--json</code></span></dt><dd><p>Print the result in a JSON representation suitable
|
|||
|
|
for automatic processing by other tools.</p></dd><dt><span class="term"><code class="option">--prebuilt-only</code> / <code class="option">-b</code></span></dt><dd><p>Show only derivations for which a substitute is
|
|||
|
|
registered, i.e., there is a pre-built binary available that can
|
|||
|
|
be downloaded in lieu of building the derivation. Thus, this
|
|||
|
|
shows all packages that probably can be installed
|
|||
|
|
quickly.</p></dd><dt><span class="term"><code class="option">--status</code>, </span><span class="term"><code class="option">-s</code></span></dt><dd><p>Print the <span class="emphasis"><em>status</em></span> of the
|
|||
|
|
derivation. The status consists of three characters. The first
|
|||
|
|
is <code class="literal">I</code> or <code class="literal">-</code>, indicating
|
|||
|
|
whether the derivation is currently installed in the current
|
|||
|
|
generation of the active profile. This is by definition the case
|
|||
|
|
for <code class="option">--installed</code>, but not for
|
|||
|
|
<code class="option">--available</code>. The second is <code class="literal">P</code>
|
|||
|
|
or <code class="literal">-</code>, indicating whether the derivation is
|
|||
|
|
present on the system. This indicates whether installation of an
|
|||
|
|
available derivation will require the derivation to be built. The
|
|||
|
|
third is <code class="literal">S</code> or <code class="literal">-</code>, indicating
|
|||
|
|
whether a substitute is available for the
|
|||
|
|
derivation.</p></dd><dt><span class="term"><code class="option">--attr-path</code>, </span><span class="term"><code class="option">-P</code></span></dt><dd><p>Print the <span class="emphasis"><em>attribute path</em></span> of
|
|||
|
|
the derivation, which can be used to unambiguously select it using
|
|||
|
|
the <a class="link" href="#opt-attr"><code class="option">--attr</code> option</a>
|
|||
|
|
available in commands that install derivations like
|
|||
|
|
<code class="literal">nix-env --install</code>. This option only works
|
|||
|
|
together with <code class="option">--available</code></p></dd><dt><span class="term"><code class="option">--no-name</code></span></dt><dd><p>Suppress printing of the <code class="literal">name</code>
|
|||
|
|
attribute of each derivation.</p></dd><dt><span class="term"><code class="option">--compare-versions</code> /
|
|||
|
|
<code class="option">-c</code></span></dt><dd><p>Compare installed versions to available versions,
|
|||
|
|
or vice versa (if <code class="option">--available</code> is given). This is
|
|||
|
|
useful for quickly seeing whether upgrades for installed
|
|||
|
|
packages are available in a Nix expression. A column is added
|
|||
|
|
with the following meaning:
|
|||
|
|
|
|||
|
|
</p><div class="variablelist"><dl class="variablelist"><dt><span class="term"><code class="literal"><</code> <em class="replaceable"><code>version</code></em></span></dt><dd><p>A newer version of the package is available
|
|||
|
|
or installed.</p></dd><dt><span class="term"><code class="literal">=</code> <em class="replaceable"><code>version</code></em></span></dt><dd><p>At most the same version of the package is
|
|||
|
|
available or installed.</p></dd><dt><span class="term"><code class="literal">></code> <em class="replaceable"><code>version</code></em></span></dt><dd><p>Only older versions of the package are
|
|||
|
|
available or installed.</p></dd><dt><span class="term"><code class="literal">- ?</code></span></dt><dd><p>No version of the package is available or
|
|||
|
|
installed.</p></dd></dl></div><p>
|
|||
|
|
|
|||
|
|
</p></dd><dt><span class="term"><code class="option">--system</code></span></dt><dd><p>Print the <code class="literal">system</code> attribute of
|
|||
|
|
the derivation.</p></dd><dt><span class="term"><code class="option">--drv-path</code></span></dt><dd><p>Print the path of the store
|
|||
|
|
derivation.</p></dd><dt><span class="term"><code class="option">--out-path</code></span></dt><dd><p>Print the output path of the
|
|||
|
|
derivation.</p></dd><dt><span class="term"><code class="option">--description</code></span></dt><dd><p>Print a short (one-line) description of the
|
|||
|
|
derivation, if available. The description is taken from the
|
|||
|
|
<code class="literal">meta.description</code> attribute of the
|
|||
|
|
derivation.</p></dd><dt><span class="term"><code class="option">--meta</code></span></dt><dd><p>Print all of the meta-attributes of the
|
|||
|
|
derivation. This option is only available with
|
|||
|
|
<code class="option">--xml</code> or <code class="option">--json</code>.</p></dd></dl></div></div><div class="refsection"><a id="idm139733299975552"></a><h3>Examples</h3><p>To show installed packages:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-env -q
|
|||
|
|
bison-1.875c
|
|||
|
|
docbook-xml-4.2
|
|||
|
|
firefox-1.0.4
|
|||
|
|
MPlayer-1.0pre7
|
|||
|
|
ORBit2-2.8.3
|
|||
|
|
<em class="replaceable"><code>…</code></em>
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
</p><p>To show available packages:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-env -qa
|
|||
|
|
firefox-1.0.7
|
|||
|
|
GConf-2.4.0.1
|
|||
|
|
MPlayer-1.0pre7
|
|||
|
|
ORBit2-2.8.3
|
|||
|
|
<em class="replaceable"><code>…</code></em>
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
</p><p>To show the status of available packages:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-env -qas
|
|||
|
|
-P- firefox-1.0.7 <em class="lineannotation"><span class="lineannotation">(not installed but present)</span></em>
|
|||
|
|
--S GConf-2.4.0.1 <em class="lineannotation"><span class="lineannotation">(not present, but there is a substitute for fast installation)</span></em>
|
|||
|
|
--S MPlayer-1.0pre3 <em class="lineannotation"><span class="lineannotation">(i.e., this is not the installed MPlayer, even though the version is the same!)</span></em>
|
|||
|
|
IP- ORBit2-2.8.3 <em class="lineannotation"><span class="lineannotation">(installed and by definition present)</span></em>
|
|||
|
|
<em class="replaceable"><code>…</code></em>
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
</p><p>To show available packages in the Nix expression <code class="filename">foo.nix</code>:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-env -f ./foo.nix -qa
|
|||
|
|
foo-1.2.3
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
</p><p>To compare installed versions to what’s available:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-env -qc
|
|||
|
|
<em class="replaceable"><code>...</code></em>
|
|||
|
|
acrobat-reader-7.0 - ? <em class="lineannotation"><span class="lineannotation">(package is not available at all)</span></em>
|
|||
|
|
autoconf-2.59 = 2.59 <em class="lineannotation"><span class="lineannotation">(same version)</span></em>
|
|||
|
|
firefox-1.0.4 < 1.0.7 <em class="lineannotation"><span class="lineannotation">(a more recent version is available)</span></em>
|
|||
|
|
<em class="replaceable"><code>...</code></em>
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
</p><p>To show all packages with “<code class="literal">zip</code>” in the name:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-env -qa '.*zip.*'
|
|||
|
|
bzip2-1.0.6
|
|||
|
|
gzip-1.6
|
|||
|
|
zip-3.0
|
|||
|
|
<em class="replaceable"><code>…</code></em>
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
</p><p>To show all packages with “<code class="literal">firefox</code>” or
|
|||
|
|
“<code class="literal">chromium</code>” in the name:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-env -qa '.*(firefox|chromium).*'
|
|||
|
|
chromium-37.0.2062.94
|
|||
|
|
chromium-beta-38.0.2125.24
|
|||
|
|
firefox-32.0.3
|
|||
|
|
firefox-with-plugins-13.0.1
|
|||
|
|
<em class="replaceable"><code>…</code></em>
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
</p><p>To show all packages in the latest revision of the Nixpkgs
|
|||
|
|
repository:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-env -f https://github.com/NixOS/nixpkgs/archive/master.tar.gz -qa
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
</p></div></div><div class="refsection"><a id="idm139733299959008"></a><h2>Operation <code class="option">--switch-profile</code></h2><div class="refsection"><a id="idm139733299958176"></a><h3>Synopsis</h3><div class="cmdsynopsis"><p><code class="command">nix-env</code> { <code class="option">--switch-profile</code> | <code class="option">-S</code> } {<em class="replaceable"><code>path</code></em>}</p></div></div><div class="refsection"><a id="idm139733299953696"></a><h3>Description</h3><p>This operation makes <em class="replaceable"><code>path</code></em> the current
|
|||
|
|
profile for the user. That is, the symlink
|
|||
|
|
<code class="filename">~/.nix-profile</code> is made to point to
|
|||
|
|
<em class="replaceable"><code>path</code></em>.</p></div><div class="refsection"><a id="idm139733299951328"></a><h3>Examples</h3><pre class="screen">
|
|||
|
|
$ nix-env -S ~/my-profile</pre></div></div><div class="refsection"><a id="idm139733299949648"></a><h2>Operation <code class="option">--list-generations</code></h2><div class="refsection"><a id="idm139733299948816"></a><h3>Synopsis</h3><div class="cmdsynopsis"><p><code class="command">nix-env</code> <code class="option">--list-generations</code> </p></div></div><div class="refsection"><a id="idm139733299946528"></a><h3>Description</h3><p>This operation print a list of all the currently existing
|
|||
|
|
generations for the active profile. These may be switched to using
|
|||
|
|
the <code class="option">--switch-generation</code> operation. It also prints
|
|||
|
|
the creation date of the generation, and indicates the current
|
|||
|
|
generation.</p></div><div class="refsection"><a id="idm139733299944800"></a><h3>Examples</h3><pre class="screen">
|
|||
|
|
$ nix-env --list-generations
|
|||
|
|
95 2004-02-06 11:48:24
|
|||
|
|
96 2004-02-06 11:49:01
|
|||
|
|
97 2004-02-06 16:22:45
|
|||
|
|
98 2004-02-06 16:24:33 (current)</pre></div></div><div class="refsection"><a id="idm139733299943088"></a><h2>Operation <code class="option">--delete-generations</code></h2><div class="refsection"><a id="idm139733299942256"></a><h3>Synopsis</h3><div class="cmdsynopsis"><p><code class="command">nix-env</code> <code class="option">--delete-generations</code> <em class="replaceable"><code>generations</code></em>... </p></div></div><div class="refsection"><a id="idm139733299938880"></a><h3>Description</h3><p>This operation deletes the specified generations of the current
|
|||
|
|
profile. The generations can be a list of generation numbers, the
|
|||
|
|
special value <code class="literal">old</code> to delete all non-current
|
|||
|
|
generations, a value such as <code class="literal">30d</code> to delete all
|
|||
|
|
generations older than the specified number of days (except for the
|
|||
|
|
generation that was active at that point in time), or a value such as
|
|||
|
|
<code class="literal">+5</code> to keep the last <code class="literal">5</code> generations
|
|||
|
|
ignoring any newer than current, e.g., if <code class="literal">30</code> is the current
|
|||
|
|
generation <code class="literal">+5</code> will delete generation <code class="literal">25</code>
|
|||
|
|
and all older generations.
|
|||
|
|
Periodically deleting old generations is important to make garbage collection
|
|||
|
|
effective.</p></div><div class="refsection"><a id="idm139733299934384"></a><h3>Examples</h3><pre class="screen">
|
|||
|
|
$ nix-env --delete-generations 3 4 8
|
|||
|
|
|
|||
|
|
$ nix-env --delete-generations +5
|
|||
|
|
|
|||
|
|
$ nix-env --delete-generations 30d
|
|||
|
|
|
|||
|
|
$ nix-env -p other_profile --delete-generations old</pre></div></div><div class="refsection"><a id="idm139733299932576"></a><h2>Operation <code class="option">--switch-generation</code></h2><div class="refsection"><a id="idm139733299931744"></a><h3>Synopsis</h3><div class="cmdsynopsis"><p><code class="command">nix-env</code> { <code class="option">--switch-generation</code> | <code class="option">-G</code> } {<em class="replaceable"><code>generation</code></em>}</p></div></div><div class="refsection"><a id="idm139733299927264"></a><h3>Description</h3><p>This operation makes generation number
|
|||
|
|
<em class="replaceable"><code>generation</code></em> the current generation of the
|
|||
|
|
active profile. That is, if the
|
|||
|
|
<code class="filename"><em class="replaceable"><code>profile</code></em></code> is the path to
|
|||
|
|
the active profile, then the symlink
|
|||
|
|
<code class="filename"><em class="replaceable"><code>profile</code></em></code> is made to
|
|||
|
|
point to
|
|||
|
|
<code class="filename"><em class="replaceable"><code>profile</code></em>-<em class="replaceable"><code>generation</code></em>-link</code>,
|
|||
|
|
which is in turn a symlink to the actual user environment in the Nix
|
|||
|
|
store.</p><p>Switching will fail if the specified generation does not exist.</p></div><div class="refsection"><a id="idm139733299922880"></a><h3>Examples</h3><pre class="screen">
|
|||
|
|
$ nix-env -G 42
|
|||
|
|
switching from generation 50 to 42</pre></div></div><div class="refsection"><a id="idm139733299921184"></a><h2>Operation <code class="option">--rollback</code></h2><div class="refsection"><a id="idm139733299920352"></a><h3>Synopsis</h3><div class="cmdsynopsis"><p><code class="command">nix-env</code> <code class="option">--rollback</code> </p></div></div><div class="refsection"><a id="idm139733299918064"></a><h3>Description</h3><p>This operation switches to the “previous” generation of the
|
|||
|
|
active profile, that is, the highest numbered generation lower than
|
|||
|
|
the current generation, if it exists. It is just a convenience
|
|||
|
|
wrapper around <code class="option">--list-generations</code> and
|
|||
|
|
<code class="option">--switch-generation</code>.</p></div><div class="refsection"><a id="idm139733299915712"></a><h3>Examples</h3><pre class="screen">
|
|||
|
|
$ nix-env --rollback
|
|||
|
|
switching from generation 92 to 91
|
|||
|
|
|
|||
|
|
$ nix-env --rollback
|
|||
|
|
error: no generation older than the current (91) exists</pre></div></div></div><div class="refentry"><div class="refentry.separator"><hr /></div><a id="sec-nix-build"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>nix-build — build a Nix expression</p></div><div class="refsynopsisdiv"><h2>Synopsis</h2><div class="cmdsynopsis"><p><code class="command">nix-build</code> [<code class="option">--help</code>] [<code class="option">--version</code>] [
|
|||
|
|
{ <code class="option">--verbose</code> | <code class="option">-v</code> }
|
|||
|
|
...] [
|
|||
|
|
<code class="option">--quiet</code>
|
|||
|
|
] [
|
|||
|
|
<code class="option">--log-format</code>
|
|||
|
|
<em class="replaceable"><code>format</code></em>
|
|||
|
|
] [
|
|||
|
|
<code class="option">--no-build-output</code> | <code class="option">-Q</code>
|
|||
|
|
] [
|
|||
|
|
{ <code class="option">--max-jobs</code> | <code class="option">-j</code> }
|
|||
|
|
<em class="replaceable"><code>number</code></em>
|
|||
|
|
] [
|
|||
|
|
<code class="option">--cores</code>
|
|||
|
|
<em class="replaceable"><code>number</code></em>
|
|||
|
|
] [
|
|||
|
|
<code class="option">--max-silent-time</code>
|
|||
|
|
<em class="replaceable"><code>number</code></em>
|
|||
|
|
] [
|
|||
|
|
<code class="option">--timeout</code>
|
|||
|
|
<em class="replaceable"><code>number</code></em>
|
|||
|
|
] [
|
|||
|
|
<code class="option">--keep-going</code> | <code class="option">-k</code>
|
|||
|
|
] [
|
|||
|
|
<code class="option">--keep-failed</code> | <code class="option">-K</code>
|
|||
|
|
] [<code class="option">--fallback</code>] [<code class="option">--readonly-mode</code>] [
|
|||
|
|
<code class="option">-I</code>
|
|||
|
|
<em class="replaceable"><code>path</code></em>
|
|||
|
|
] [
|
|||
|
|
<code class="option">--option</code>
|
|||
|
|
<em class="replaceable"><code>name</code></em>
|
|||
|
|
<em class="replaceable"><code>value</code></em>
|
|||
|
|
]<br /> [<code class="option">--arg</code> <em class="replaceable"><code>name</code></em> <em class="replaceable"><code>value</code></em>] [<code class="option">--argstr</code> <em class="replaceable"><code>name</code></em> <em class="replaceable"><code>value</code></em>] [
|
|||
|
|
{ <code class="option">--attr</code> | <code class="option">-A</code> }
|
|||
|
|
<em class="replaceable"><code>attrPath</code></em>
|
|||
|
|
] [<code class="option">--no-out-link</code>] [<code class="option">--dry-run</code>] [
|
|||
|
|
{ <code class="option">--out-link</code> | <code class="option">-o</code> }
|
|||
|
|
<em class="replaceable"><code>outlink</code></em>
|
|||
|
|
] <em class="replaceable"><code>paths</code></em>... </p></div></div><div class="refsection"><a id="idm139733299874432"></a><h2>Description</h2><p>The <span class="command"><strong>nix-build</strong></span> command builds the derivations
|
|||
|
|
described by the Nix expressions in <em class="replaceable"><code>paths</code></em>.
|
|||
|
|
If the build succeeds, it places a symlink to the result in the
|
|||
|
|
current directory. The symlink is called <code class="filename">result</code>.
|
|||
|
|
If there are multiple Nix expressions, or the Nix expressions evaluate
|
|||
|
|
to multiple derivations, multiple sequentially numbered symlinks are
|
|||
|
|
created (<code class="filename">result</code>, <code class="filename">result-2</code>,
|
|||
|
|
and so on).</p><p>If no <em class="replaceable"><code>paths</code></em> are specified, then
|
|||
|
|
<span class="command"><strong>nix-build</strong></span> will use <code class="filename">default.nix</code>
|
|||
|
|
in the current directory, if it exists.</p><p>If an element of <em class="replaceable"><code>paths</code></em> starts with
|
|||
|
|
<code class="literal">http://</code> or <code class="literal">https://</code>, it is
|
|||
|
|
interpreted as the URL of a tarball that will be downloaded and
|
|||
|
|
unpacked to a temporary location. The tarball must include a single
|
|||
|
|
top-level directory containing at least a file named
|
|||
|
|
<code class="filename">default.nix</code>.</p><p><span class="command"><strong>nix-build</strong></span> is essentially a wrapper around
|
|||
|
|
<a class="link" href="#sec-nix-instantiate" title="nix-instantiate"><span class="command"><strong>nix-instantiate</strong></span></a>
|
|||
|
|
(to translate a high-level Nix expression to a low-level store
|
|||
|
|
derivation) and <a class="link" href="#rsec-nix-store-realise" title="Operation --realise"><span class="command"><strong>nix-store
|
|||
|
|
--realise</strong></span></a> (to build the store derivation).</p><div class="warning"><h3 class="title">Warning</h3><p>The result of the build is automatically registered as
|
|||
|
|
a root of the Nix garbage collector. This root disappears
|
|||
|
|
automatically when the <code class="filename">result</code> symlink is deleted
|
|||
|
|
or renamed. So don’t rename the symlink.</p></div></div><div class="refsection"><a id="idm139733299863072"></a><h2>Options</h2><p>All options not listed here are passed to <span class="command"><strong>nix-store
|
|||
|
|
--realise</strong></span>, except for <code class="option">--arg</code> and
|
|||
|
|
<code class="option">--attr</code> / <code class="option">-A</code> which are passed to
|
|||
|
|
<span class="command"><strong>nix-instantiate</strong></span>. <span class="phrase">See
|
|||
|
|
also <a class="xref" href="#sec-common-options" title="Chapter 20. Common Options">Chapter 20, <em>Common Options</em></a>.</span></p><div class="variablelist"><dl class="variablelist"><dt><span class="term"><code class="option">--no-out-link</code></span></dt><dd><p>Do not create a symlink to the output path. Note
|
|||
|
|
that as a result the output does not become a root of the garbage
|
|||
|
|
collector, and so might be deleted by <span class="command"><strong>nix-store
|
|||
|
|
--gc</strong></span>.</p></dd><dt><span class="term"><code class="option">--dry-run</code></span></dt><dd><p>Show what store paths would be built or downloaded.</p></dd><dt><a id="opt-out-link"></a><span class="term"><code class="option">--out-link</code> /
|
|||
|
|
<code class="option">-o</code> <em class="replaceable"><code>outlink</code></em></span></dt><dd><p>Change the name of the symlink to the output path
|
|||
|
|
created from <code class="filename">result</code> to
|
|||
|
|
<em class="replaceable"><code>outlink</code></em>.</p></dd></dl></div><p>The following common options are supported:</p></div><div class="refsection"><a id="idm139733299851056"></a><h2>Examples</h2><pre class="screen">
|
|||
|
|
$ nix-build '<nixpkgs>' -A firefox
|
|||
|
|
store derivation is /nix/store/qybprl8sz2lc...-firefox-1.5.0.7.drv
|
|||
|
|
/nix/store/d18hyl92g30l...-firefox-1.5.0.7
|
|||
|
|
|
|||
|
|
$ ls -l result
|
|||
|
|
lrwxrwxrwx <em class="replaceable"><code>...</code></em> result -> /nix/store/d18hyl92g30l...-firefox-1.5.0.7
|
|||
|
|
|
|||
|
|
$ ls ./result/bin/
|
|||
|
|
firefox firefox-config</pre><p>If a derivation has multiple outputs,
|
|||
|
|
<span class="command"><strong>nix-build</strong></span> will build the default (first) output.
|
|||
|
|
You can also build all outputs:
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-build '<nixpkgs>' -A openssl.all
|
|||
|
|
</pre><p>
|
|||
|
|
This will create a symlink for each output named
|
|||
|
|
<code class="filename">result-<em class="replaceable"><code>outputname</code></em></code>.
|
|||
|
|
The suffix is omitted if the output name is <code class="literal">out</code>.
|
|||
|
|
So if <code class="literal">openssl</code> has outputs <code class="literal">out</code>,
|
|||
|
|
<code class="literal">bin</code> and <code class="literal">man</code>,
|
|||
|
|
<span class="command"><strong>nix-build</strong></span> will create symlinks
|
|||
|
|
<code class="literal">result</code>, <code class="literal">result-bin</code> and
|
|||
|
|
<code class="literal">result-man</code>. It’s also possible to build a specific
|
|||
|
|
output:
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-build '<nixpkgs>' -A openssl.man
|
|||
|
|
</pre><p>
|
|||
|
|
This will create a symlink <code class="literal">result-man</code>.</p><p>Build a Nix expression given on the command line:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-build -E 'with import <nixpkgs> { }; runCommand "foo" { } "echo bar > $out"'
|
|||
|
|
$ cat ./result
|
|||
|
|
bar
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
</p><p>Build the GNU Hello package from the latest revision of the
|
|||
|
|
master branch of Nixpkgs:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-build https://github.com/NixOS/nixpkgs/archive/master.tar.gz -A hello
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
</p></div></div><div class="refentry"><div class="refentry.separator"><hr /></div><a id="sec-nix-shell"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>nix-shell — start an interactive shell based on a Nix expression</p></div><div class="refsynopsisdiv"><h2>Synopsis</h2><div class="cmdsynopsis"><p><code class="command">nix-shell</code> [<code class="option">--arg</code> <em class="replaceable"><code>name</code></em> <em class="replaceable"><code>value</code></em>] [<code class="option">--argstr</code> <em class="replaceable"><code>name</code></em> <em class="replaceable"><code>value</code></em>] [
|
|||
|
|
{ <code class="option">--attr</code> | <code class="option">-A</code> }
|
|||
|
|
<em class="replaceable"><code>attrPath</code></em>
|
|||
|
|
] [<code class="option">--command</code> <em class="replaceable"><code>cmd</code></em>] [<code class="option">--run</code> <em class="replaceable"><code>cmd</code></em>] [<code class="option">--exclude</code> <em class="replaceable"><code>regexp</code></em>] [<code class="option">--pure</code>] [<code class="option">--keep</code> <em class="replaceable"><code>name</code></em>] {
|
|||
|
|
{ <code class="option">--packages</code> | <code class="option">-p</code> }
|
|||
|
|
|
|||
|
|
{ <em class="replaceable"><code>packages</code></em> | <em class="replaceable"><code>expressions</code></em> }
|
|||
|
|
...
|
|||
|
|
| [<em class="replaceable"><code>path</code></em>]}</p></div></div><div class="refsection"><a id="idm139733299816608"></a><h2>Description</h2><p>The command <span class="command"><strong>nix-shell</strong></span> will build the
|
|||
|
|
dependencies of the specified derivation, but not the derivation
|
|||
|
|
itself. It will then start an interactive shell in which all
|
|||
|
|
environment variables defined by the derivation
|
|||
|
|
<em class="replaceable"><code>path</code></em> have been set to their corresponding
|
|||
|
|
values, and the script <code class="literal">$stdenv/setup</code> has been
|
|||
|
|
sourced. This is useful for reproducing the environment of a
|
|||
|
|
derivation for development.</p><p>If <em class="replaceable"><code>path</code></em> is not given,
|
|||
|
|
<span class="command"><strong>nix-shell</strong></span> defaults to
|
|||
|
|
<code class="filename">shell.nix</code> if it exists, and
|
|||
|
|
<code class="filename">default.nix</code> otherwise.</p><p>If <em class="replaceable"><code>path</code></em> starts with
|
|||
|
|
<code class="literal">http://</code> or <code class="literal">https://</code>, it is
|
|||
|
|
interpreted as the URL of a tarball that will be downloaded and
|
|||
|
|
unpacked to a temporary location. The tarball must include a single
|
|||
|
|
top-level directory containing at least a file named
|
|||
|
|
<code class="filename">default.nix</code>.</p><p>If the derivation defines the variable
|
|||
|
|
<code class="varname">shellHook</code>, it will be evaluated after
|
|||
|
|
<code class="literal">$stdenv/setup</code> has been sourced. Since this hook is
|
|||
|
|
not executed by regular Nix builds, it allows you to perform
|
|||
|
|
initialisation specific to <span class="command"><strong>nix-shell</strong></span>. For example,
|
|||
|
|
the derivation attribute
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
shellHook =
|
|||
|
|
''
|
|||
|
|
echo "Hello shell"
|
|||
|
|
'';
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
will cause <span class="command"><strong>nix-shell</strong></span> to print <code class="literal">Hello shell</code>.</p></div><div class="refsection"><a id="idm139733299806096"></a><h2>Options</h2><p>All options not listed here are passed to <span class="command"><strong>nix-store
|
|||
|
|
--realise</strong></span>, except for <code class="option">--arg</code> and
|
|||
|
|
<code class="option">--attr</code> / <code class="option">-A</code> which are passed to
|
|||
|
|
<span class="command"><strong>nix-instantiate</strong></span>. <span class="phrase">See
|
|||
|
|
also <a class="xref" href="#sec-common-options" title="Chapter 20. Common Options">Chapter 20, <em>Common Options</em></a>.</span></p><div class="variablelist"><dl class="variablelist"><dt><span class="term"><code class="option">--command</code> <em class="replaceable"><code>cmd</code></em></span></dt><dd><p>In the environment of the derivation, run the
|
|||
|
|
shell command <em class="replaceable"><code>cmd</code></em>. This command is
|
|||
|
|
executed in an interactive shell. (Use <code class="option">--run</code> to
|
|||
|
|
use a non-interactive shell instead.) However, a call to
|
|||
|
|
<code class="literal">exit</code> is implicitly added to the command, so the
|
|||
|
|
shell will exit after running the command. To prevent this, add
|
|||
|
|
<code class="literal">return</code> at the end; e.g. <code class="literal">--command
|
|||
|
|
"echo Hello; return"</code> will print <code class="literal">Hello</code>
|
|||
|
|
and then drop you into the interactive shell. This can be useful
|
|||
|
|
for doing any additional initialisation.</p></dd><dt><span class="term"><code class="option">--run</code> <em class="replaceable"><code>cmd</code></em></span></dt><dd><p>Like <code class="option">--command</code>, but executes the
|
|||
|
|
command in a non-interactive shell. This means (among other
|
|||
|
|
things) that if you hit Ctrl-C while the command is running, the
|
|||
|
|
shell exits.</p></dd><dt><span class="term"><code class="option">--exclude</code> <em class="replaceable"><code>regexp</code></em></span></dt><dd><p>Do not build any dependencies whose store path
|
|||
|
|
matches the regular expression <em class="replaceable"><code>regexp</code></em>.
|
|||
|
|
This option may be specified multiple times.</p></dd><dt><span class="term"><code class="option">--pure</code></span></dt><dd><p>If this flag is specified, the environment is
|
|||
|
|
almost entirely cleared before the interactive shell is started,
|
|||
|
|
so you get an environment that more closely corresponds to the
|
|||
|
|
“real” Nix build. A few variables, in particular
|
|||
|
|
<code class="envar">HOME</code>, <code class="envar">USER</code> and
|
|||
|
|
<code class="envar">DISPLAY</code>, are retained. Note that
|
|||
|
|
<code class="filename">~/.bashrc</code> and (depending on your Bash
|
|||
|
|
installation) <code class="filename">/etc/bashrc</code> are still sourced,
|
|||
|
|
so any variables set there will affect the interactive
|
|||
|
|
shell.</p></dd><dt><span class="term"><code class="option">--packages</code> / <code class="option">-p</code> <em class="replaceable"><code>packages</code></em>…</span></dt><dd><p>Set up an environment in which the specified
|
|||
|
|
packages are present. The command line arguments are interpreted
|
|||
|
|
as attribute names inside the Nix Packages collection. Thus,
|
|||
|
|
<code class="literal">nix-shell -p libjpeg openjdk</code> will start a shell
|
|||
|
|
in which the packages denoted by the attribute names
|
|||
|
|
<code class="varname">libjpeg</code> and <code class="varname">openjdk</code> are
|
|||
|
|
present.</p></dd><dt><span class="term"><code class="option">-i</code> <em class="replaceable"><code>interpreter</code></em></span></dt><dd><p>The chained script interpreter to be invoked by
|
|||
|
|
<span class="command"><strong>nix-shell</strong></span>. Only applicable in
|
|||
|
|
<code class="literal">#!</code>-scripts (described <a class="link" href="#ssec-nix-shell-shebang" title="Use as a #!-interpreter">below</a>).</p></dd><dt><span class="term"><code class="option">--keep</code> <em class="replaceable"><code>name</code></em></span></dt><dd><p>When a <code class="option">--pure</code> shell is started,
|
|||
|
|
keep the listed environment variables.</p></dd></dl></div><p>The following common options are supported:</p></div><div class="refsection"><a id="idm139733299777888"></a><h2>Environment variables</h2><div class="variablelist"><dl class="variablelist"><dt><span class="term"><code class="envar">NIX_BUILD_SHELL</code></span></dt><dd><p>Shell used to start the interactive environment.
|
|||
|
|
Defaults to the <span class="command"><strong>bash</strong></span> found in <code class="envar">PATH</code>.</p></dd></dl></div></div><div class="refsection"><a id="idm139733299774576"></a><h2>Examples</h2><p>To build the dependencies of the package Pan, and start an
|
|||
|
|
interactive shell in which to build it:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-shell '<nixpkgs>' -A pan
|
|||
|
|
[nix-shell]$ unpackPhase
|
|||
|
|
[nix-shell]$ cd pan-*
|
|||
|
|
[nix-shell]$ configurePhase
|
|||
|
|
[nix-shell]$ buildPhase
|
|||
|
|
[nix-shell]$ ./pan/gui/pan
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
To clear the environment first, and do some additional automatic
|
|||
|
|
initialisation of the interactive shell:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-shell '<nixpkgs>' -A pan --pure \
|
|||
|
|
--command 'export NIX_DEBUG=1; export NIX_CORES=8; return'
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
Nix expressions can also be given on the command line using the
|
|||
|
|
<span class="command"><strong>-E</strong></span> and <span class="command"><strong>-p</strong></span> flags.
|
|||
|
|
For instance, the following starts a shell containing the packages
|
|||
|
|
<code class="literal">sqlite</code> and <code class="literal">libX11</code>:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-shell -E 'with import <nixpkgs> { }; runCommand "dummy" { buildInputs = [ sqlite xorg.libX11 ]; } ""'
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
A shorter way to do the same is:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-shell -p sqlite xorg.libX11
|
|||
|
|
[nix-shell]$ echo $NIX_LDFLAGS
|
|||
|
|
… -L/nix/store/j1zg5v…-sqlite-3.8.0.2/lib -L/nix/store/0gmcz9…-libX11-1.6.1/lib …
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
Note that <span class="command"><strong>-p</strong></span> accepts multiple full nix expressions that
|
|||
|
|
are valid in the <code class="literal">buildInputs = [ ... ]</code> shown above,
|
|||
|
|
not only package names. So the following is also legal:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-shell -p sqlite 'git.override { withManual = false; }'
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
The <span class="command"><strong>-p</strong></span> flag looks up Nixpkgs in the Nix search
|
|||
|
|
path. You can override it by passing <code class="option">-I</code> or setting
|
|||
|
|
<code class="envar">NIX_PATH</code>. For example, the following gives you a shell
|
|||
|
|
containing the Pan package from a specific revision of Nixpkgs:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-shell -p pan -I nixpkgs=https://github.com/NixOS/nixpkgs/archive/8a3eea054838b55aca962c3fbde9c83c102b8bf2.tar.gz
|
|||
|
|
|
|||
|
|
[nix-shell:~]$ pan --version
|
|||
|
|
Pan 0.139
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
</p></div><div class="refsection"><a id="ssec-nix-shell-shebang"></a><h2>Use as a <code class="literal">#!</code>-interpreter</h2><p>You can use <span class="command"><strong>nix-shell</strong></span> as a script interpreter
|
|||
|
|
to allow scripts written in arbitrary languages to obtain their own
|
|||
|
|
dependencies via Nix. This is done by starting the script with the
|
|||
|
|
following lines:
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
#! /usr/bin/env nix-shell
|
|||
|
|
#! nix-shell -i <em class="replaceable"><code>real-interpreter</code></em> -p <em class="replaceable"><code>packages</code></em>
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
where <em class="replaceable"><code>real-interpreter</code></em> is the “real” script
|
|||
|
|
interpreter that will be invoked by <span class="command"><strong>nix-shell</strong></span> after
|
|||
|
|
it has obtained the dependencies and initialised the environment, and
|
|||
|
|
<em class="replaceable"><code>packages</code></em> are the attribute names of the
|
|||
|
|
dependencies in Nixpkgs.</p><p>The lines starting with <code class="literal">#! nix-shell</code> specify
|
|||
|
|
<span class="command"><strong>nix-shell</strong></span> options (see above). Note that you cannot
|
|||
|
|
write <code class="literal">#! /usr/bin/env nix-shell -i ...</code> because
|
|||
|
|
many operating systems only allow one argument in
|
|||
|
|
<code class="literal">#!</code> lines.</p><p>For example, here is a Python script that depends on Python and
|
|||
|
|
the <code class="literal">prettytable</code> package:
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
#! /usr/bin/env nix-shell
|
|||
|
|
#! nix-shell -i python -p python pythonPackages.prettytable
|
|||
|
|
|
|||
|
|
import prettytable
|
|||
|
|
|
|||
|
|
# Print a simple table.
|
|||
|
|
t = prettytable.PrettyTable(["N", "N^2"])
|
|||
|
|
for n in range(1, 10): t.add_row([n, n * n])
|
|||
|
|
print t
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
</p><p>Similarly, the following is a Perl script that specifies that it
|
|||
|
|
requires Perl and the <code class="literal">HTML::TokeParser::Simple</code> and
|
|||
|
|
<code class="literal">LWP</code> packages:
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
#! /usr/bin/env nix-shell
|
|||
|
|
#! nix-shell -i perl -p perl perlPackages.HTMLTokeParserSimple perlPackages.LWP
|
|||
|
|
|
|||
|
|
use HTML::TokeParser::Simple;
|
|||
|
|
|
|||
|
|
# Fetch nixos.org and print all hrefs.
|
|||
|
|
my $p = HTML::TokeParser::Simple->new(url => 'http://nixos.org/');
|
|||
|
|
|
|||
|
|
while (my $token = $p->get_tag("a")) {
|
|||
|
|
my $href = $token->get_attr("href");
|
|||
|
|
print "$href\n" if $href;
|
|||
|
|
}
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
</p><p>Sometimes you need to pass a simple Nix expression to customize
|
|||
|
|
a package like Terraform:
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
#! /usr/bin/env nix-shell
|
|||
|
|
#! nix-shell -i bash -p "terraform.withPlugins (plugins: [ plugins.openstack ])"
|
|||
|
|
|
|||
|
|
terraform apply
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
</p><div class="note"><h3 class="title">Note</h3><p>You must use double quotes (<code class="literal">"</code>) when
|
|||
|
|
passing a simple Nix expression in a nix-shell shebang.</p></div><p>
|
|||
|
|
</p><p>Finally, using the merging of multiple nix-shell shebangs the
|
|||
|
|
following Haskell script uses a specific branch of Nixpkgs/NixOS (the
|
|||
|
|
18.03 stable branch):
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
#! /usr/bin/env nix-shell
|
|||
|
|
#! nix-shell -i runghc -p "haskellPackages.ghcWithPackages (ps: [ps.HTTP ps.tagsoup])"
|
|||
|
|
#! nix-shell -I nixpkgs=https://github.com/NixOS/nixpkgs/archive/nixos-18.03.tar.gz
|
|||
|
|
|
|||
|
|
import Network.HTTP
|
|||
|
|
import Text.HTML.TagSoup
|
|||
|
|
|
|||
|
|
-- Fetch nixos.org and print all hrefs.
|
|||
|
|
main = do
|
|||
|
|
resp <- Network.HTTP.simpleHTTP (getRequest "http://nixos.org/")
|
|||
|
|
body <- getResponseBody resp
|
|||
|
|
let tags = filter (isTagOpenName "a") $ parseTags body
|
|||
|
|
let tags' = map (fromAttrib "href") tags
|
|||
|
|
mapM_ putStrLn $ filter (/= "") tags'
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
If you want to be even more precise, you can specify a specific
|
|||
|
|
revision of Nixpkgs:
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
#! nix-shell -I nixpkgs=https://github.com/NixOS/nixpkgs/archive/0672315759b3e15e2121365f067c1c8c56bb4722.tar.gz
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
</p><p>The examples above all used <code class="option">-p</code> to get
|
|||
|
|
dependencies from Nixpkgs. You can also use a Nix expression to build
|
|||
|
|
your own dependencies. For example, the Python example could have been
|
|||
|
|
written as:
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
#! /usr/bin/env nix-shell
|
|||
|
|
#! nix-shell deps.nix -i python
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
where the file <code class="filename">deps.nix</code> in the same directory
|
|||
|
|
as the <code class="literal">#!</code>-script contains:
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
with import <nixpkgs> {};
|
|||
|
|
|
|||
|
|
runCommand "dummy" { buildInputs = [ python pythonPackages.prettytable ]; } ""
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
</p></div></div><div class="refentry"><div class="refentry.separator"><hr /></div><a id="sec-nix-store"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>nix-store — manipulate or query the Nix store</p></div><div class="refsynopsisdiv"><h2>Synopsis</h2><div class="cmdsynopsis"><p><code class="command">nix-store</code> [<code class="option">--help</code>] [<code class="option">--version</code>] [
|
|||
|
|
{ <code class="option">--verbose</code> | <code class="option">-v</code> }
|
|||
|
|
...] [
|
|||
|
|
<code class="option">--quiet</code>
|
|||
|
|
] [
|
|||
|
|
<code class="option">--log-format</code>
|
|||
|
|
<em class="replaceable"><code>format</code></em>
|
|||
|
|
] [
|
|||
|
|
<code class="option">--no-build-output</code> | <code class="option">-Q</code>
|
|||
|
|
] [
|
|||
|
|
{ <code class="option">--max-jobs</code> | <code class="option">-j</code> }
|
|||
|
|
<em class="replaceable"><code>number</code></em>
|
|||
|
|
] [
|
|||
|
|
<code class="option">--cores</code>
|
|||
|
|
<em class="replaceable"><code>number</code></em>
|
|||
|
|
] [
|
|||
|
|
<code class="option">--max-silent-time</code>
|
|||
|
|
<em class="replaceable"><code>number</code></em>
|
|||
|
|
] [
|
|||
|
|
<code class="option">--timeout</code>
|
|||
|
|
<em class="replaceable"><code>number</code></em>
|
|||
|
|
] [
|
|||
|
|
<code class="option">--keep-going</code> | <code class="option">-k</code>
|
|||
|
|
] [
|
|||
|
|
<code class="option">--keep-failed</code> | <code class="option">-K</code>
|
|||
|
|
] [<code class="option">--fallback</code>] [<code class="option">--readonly-mode</code>] [
|
|||
|
|
<code class="option">-I</code>
|
|||
|
|
<em class="replaceable"><code>path</code></em>
|
|||
|
|
] [
|
|||
|
|
<code class="option">--option</code>
|
|||
|
|
<em class="replaceable"><code>name</code></em>
|
|||
|
|
<em class="replaceable"><code>value</code></em>
|
|||
|
|
]<br /> [<code class="option">--add-root</code> <em class="replaceable"><code>path</code></em>] [<code class="option">--indirect</code>] <em class="replaceable"><code>operation</code></em> [<em class="replaceable"><code>options</code></em>...] [<em class="replaceable"><code>arguments</code></em>...]</p></div></div><div class="refsection"><a id="idm139733299713504"></a><h2>Description</h2><p>The command <span class="command"><strong>nix-store</strong></span> performs primitive
|
|||
|
|
operations on the Nix store. You generally do not need to run this
|
|||
|
|
command manually.</p><p><span class="command"><strong>nix-store</strong></span> takes exactly one
|
|||
|
|
<span class="emphasis"><em>operation</em></span> flag which indicates the subcommand to
|
|||
|
|
be performed. These are documented below.</p></div><div class="refsection"><a id="idm139733299710208"></a><h2>Common options</h2><p>This section lists the options that are common to all
|
|||
|
|
operations. These options are allowed for every subcommand, though
|
|||
|
|
they may not always have an effect. <span class="phrase">See
|
|||
|
|
also <a class="xref" href="#sec-common-options" title="Chapter 20. Common Options">Chapter 20, <em>Common Options</em></a> for a list of common
|
|||
|
|
options.</span></p><div class="variablelist"><dl class="variablelist"><dt><a id="opt-add-root"></a><span class="term"><code class="option">--add-root</code> <em class="replaceable"><code>path</code></em></span></dt><dd><p>Causes the result of a realisation
|
|||
|
|
(<code class="option">--realise</code> and <code class="option">--force-realise</code>)
|
|||
|
|
to be registered as a root of the garbage collector<span class="phrase"> (see <a class="xref" href="#ssec-gc-roots" title="11.1. Garbage Collector Roots">Section 11.1, “Garbage Collector Roots”</a>)</span>. The root is stored in
|
|||
|
|
<em class="replaceable"><code>path</code></em>, which must be inside a directory
|
|||
|
|
that is scanned for roots by the garbage collector (i.e.,
|
|||
|
|
typically in a subdirectory of
|
|||
|
|
<code class="filename">/nix/var/nix/gcroots/</code>)
|
|||
|
|
<span class="emphasis"><em>unless</em></span> the <code class="option">--indirect</code> flag
|
|||
|
|
is used.</p><p>If there are multiple results, then multiple symlinks will
|
|||
|
|
be created by sequentially numbering symlinks beyond the first one
|
|||
|
|
(e.g., <code class="filename">foo</code>, <code class="filename">foo-2</code>,
|
|||
|
|
<code class="filename">foo-3</code>, and so on).</p></dd><dt><span class="term"><code class="option">--indirect</code></span></dt><dd><p>In conjunction with <code class="option">--add-root</code>, this option
|
|||
|
|
allows roots to be stored <span class="emphasis"><em>outside</em></span> of the GC
|
|||
|
|
roots directory. This is useful for commands such as
|
|||
|
|
<span class="command"><strong>nix-build</strong></span> that place a symlink to the build
|
|||
|
|
result in the current directory; such a build result should not be
|
|||
|
|
garbage-collected unless the symlink is removed.</p><p>The <code class="option">--indirect</code> flag causes a uniquely named
|
|||
|
|
symlink to <em class="replaceable"><code>path</code></em> to be stored in
|
|||
|
|
<code class="filename">/nix/var/nix/gcroots/auto/</code>. For instance,
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-store --add-root /home/eelco/bla/result --indirect -r <em class="replaceable"><code>...</code></em>
|
|||
|
|
|
|||
|
|
$ ls -l /nix/var/nix/gcroots/auto
|
|||
|
|
lrwxrwxrwx 1 ... 2005-03-13 21:10 dn54lcypm8f8... -> /home/eelco/bla/result
|
|||
|
|
|
|||
|
|
$ ls -l /home/eelco/bla/result
|
|||
|
|
lrwxrwxrwx 1 ... 2005-03-13 21:10 /home/eelco/bla/result -> /nix/store/1r11343n6qd4...-f-spot-0.0.10</pre><p>
|
|||
|
|
|
|||
|
|
Thus, when <code class="filename">/home/eelco/bla/result</code> is removed,
|
|||
|
|
the GC root in the <code class="filename">auto</code> directory becomes a
|
|||
|
|
dangling symlink and will be ignored by the collector.</p><div class="warning"><h3 class="title">Warning</h3><p>Note that it is not possible to move or rename
|
|||
|
|
indirect GC roots, since the symlink in the
|
|||
|
|
<code class="filename">auto</code> directory will still point to the old
|
|||
|
|
location.</p></div></dd></dl></div></div><div class="refsection"><a id="rsec-nix-store-realise"></a><h2>Operation <code class="option">--realise</code></h2><div class="refsection"><a id="idm139733299689136"></a><h3>Synopsis</h3><div class="cmdsynopsis"><p><code class="command">nix-store</code> { <code class="option">--realise</code> | <code class="option">-r</code> } <em class="replaceable"><code>paths</code></em>... [<code class="option">--dry-run</code>]</p></div></div><div class="refsection"><a id="idm139733299683808"></a><h3>Description</h3><p>The operation <code class="option">--realise</code> essentially “builds”
|
|||
|
|
the specified store paths. Realisation is a somewhat overloaded term:
|
|||
|
|
|
|||
|
|
</p><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><p>If the store path is a
|
|||
|
|
<span class="emphasis"><em>derivation</em></span>, realisation ensures that the output
|
|||
|
|
paths of the derivation are <a class="link" href="#gloss-validity" title="validity">valid</a> (i.e., the output path and its
|
|||
|
|
closure exist in the file system). This can be done in several
|
|||
|
|
ways. First, it is possible that the outputs are already valid, in
|
|||
|
|
which case we are done immediately. Otherwise, there may be <a class="link" href="#gloss-substitute" title="substitute">substitutes</a> that produce the
|
|||
|
|
outputs (e.g., by downloading them). Finally, the outputs can be
|
|||
|
|
produced by performing the build action described by the
|
|||
|
|
derivation.</p></li><li class="listitem"><p>If the store path is not a derivation, realisation
|
|||
|
|
ensures that the specified path is valid (i.e., it and its closure
|
|||
|
|
exist in the file system). If the path is already valid, we are
|
|||
|
|
done immediately. Otherwise, the path and any missing paths in its
|
|||
|
|
closure may be produced through substitutes. If there are no
|
|||
|
|
(successful) subsitutes, realisation fails.</p></li></ul></div><p>
|
|||
|
|
|
|||
|
|
</p><p>The output path of each derivation is printed on standard
|
|||
|
|
output. (For non-derivations argument, the argument itself is
|
|||
|
|
printed.)</p><p>The following flags are available:</p><div class="variablelist"><dl class="variablelist"><dt><span class="term"><code class="option">--dry-run</code></span></dt><dd><p>Print on standard error a description of what
|
|||
|
|
packages would be built or downloaded, without actually performing
|
|||
|
|
the operation.</p></dd><dt><span class="term"><code class="option">--ignore-unknown</code></span></dt><dd><p>If a non-derivation path does not have a
|
|||
|
|
substitute, then silently ignore it.</p></dd><dt><span class="term"><code class="option">--check</code></span></dt><dd><p>This option allows you to check whether a
|
|||
|
|
derivation is deterministic. It rebuilds the specified derivation
|
|||
|
|
and checks whether the result is bitwise-identical with the
|
|||
|
|
existing outputs, printing an error if that’s not the case. The
|
|||
|
|
outputs of the specified derivation must already exist. When used
|
|||
|
|
with <code class="option">-K</code>, if an output path is not identical to
|
|||
|
|
the corresponding output from the previous build, the new output
|
|||
|
|
path is left in
|
|||
|
|
<code class="filename">/nix/store/<em class="replaceable"><code>name</code></em>.check.</code></p><p>See also the <code class="option">build-repeat</code> configuration
|
|||
|
|
option, which repeats a derivation a number of times and prevents
|
|||
|
|
its outputs from being registered as “valid” in the Nix store
|
|||
|
|
unless they are identical.</p></dd></dl></div><p>Special exit codes:</p><div class="variablelist"><dl class="variablelist"><dt><span class="term"><code class="literal">100</code></span></dt><dd><p>Generic build failure, the builder process
|
|||
|
|
returned with a non-zero exit code.</p></dd><dt><span class="term"><code class="literal">101</code></span></dt><dd><p>Build timeout, the build was aborted because it
|
|||
|
|
did not complete within the specified <a class="link" href="#conf-timeout"><code class="literal">timeout</code></a>.
|
|||
|
|
</p></dd><dt><span class="term"><code class="literal">102</code></span></dt><dd><p>Hash mismatch, the build output was rejected
|
|||
|
|
because it does not match the specified <a class="link" href="#fixed-output-drvs"><code class="varname">outputHash</code></a>.
|
|||
|
|
</p></dd><dt><span class="term"><code class="literal">104</code></span></dt><dd><p>Not deterministic, the build succeeded in check
|
|||
|
|
mode but the resulting output is not binary reproducable.</p></dd></dl></div><p>With the <code class="option">--keep-going</code> flag it's possible for
|
|||
|
|
multiple failures to occur, in this case the 1xx status codes are or combined
|
|||
|
|
using binary or. </p><pre class="screen">
|
|||
|
|
1100100
|
|||
|
|
^^^^
|
|||
|
|
|||`- timeout
|
|||
|
|
||`-- output hash mismatch
|
|||
|
|
|`--- build failure
|
|||
|
|
`---- not deterministic
|
|||
|
|
</pre></div><div class="refsection"><a id="idm139733299659648"></a><h3>Examples</h3><p>This operation is typically used to build store derivations
|
|||
|
|
produced by <a class="link" href="#sec-nix-instantiate" title="nix-instantiate"><span class="command"><strong>nix-instantiate</strong></span></a>:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-store -r $(nix-instantiate ./test.nix)
|
|||
|
|
/nix/store/31axcgrlbfsxzmfff1gyj1bf62hvkby2-aterm-2.3.1</pre><p>
|
|||
|
|
|
|||
|
|
This is essentially what <a class="link" href="#sec-nix-build" title="nix-build"><span class="command"><strong>nix-build</strong></span></a> does.</p><p>To test whether a previously-built derivation is deterministic:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-build '<nixpkgs>' -A hello --check -K
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
</p></div></div><div class="refsection"><a id="rsec-nix-store-serve"></a><h2>Operation <code class="option">--serve</code></h2><div class="refsection"><a id="idm139733299653424"></a><h3>Synopsis</h3><div class="cmdsynopsis"><p><code class="command">nix-store</code> <code class="option">--serve</code> [<code class="option">--write</code>]</p></div></div><div class="refsection"><a id="idm139733299650592"></a><h3>Description</h3><p>The operation <code class="option">--serve</code> provides access to
|
|||
|
|
the Nix store over stdin and stdout, and is intended to be used
|
|||
|
|
as a means of providing Nix store access to a restricted ssh user.
|
|||
|
|
</p><p>The following flags are available:</p><div class="variablelist"><dl class="variablelist"><dt><span class="term"><code class="option">--write</code></span></dt><dd><p>Allow the connected client to request the realization
|
|||
|
|
of derivations. In effect, this can be used to make the host act
|
|||
|
|
as a remote builder.</p></dd></dl></div></div><div class="refsection"><a id="idm139733299646640"></a><h3>Examples</h3><p>To turn a host into a build server, the
|
|||
|
|
<code class="filename">authorized_keys</code> file can be used to provide build
|
|||
|
|
access to a given SSH public key:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ cat <<EOF >>/root/.ssh/authorized_keys
|
|||
|
|
command="nice -n20 nix-store --serve --write" ssh-rsa AAAAB3NzaC1yc2EAAAA...
|
|||
|
|
EOF
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
</p></div></div><div class="refsection"><a id="rsec-nix-store-gc"></a><h2>Operation <code class="option">--gc</code></h2><div class="refsection"><a id="idm139733299642624"></a><h3>Synopsis</h3><div class="cmdsynopsis"><p><code class="command">nix-store</code> <code class="option">--gc</code> [ <code class="option">--print-roots</code> | <code class="option">--print-live</code> | <code class="option">--print-dead</code> ] [<code class="option">--max-freed</code> <em class="replaceable"><code>bytes</code></em>]</p></div></div><div class="refsection"><a id="idm139733299636544"></a><h3>Description</h3><p>Without additional flags, the operation <code class="option">--gc</code>
|
|||
|
|
performs a garbage collection on the Nix store. That is, all paths in
|
|||
|
|
the Nix store not reachable via file system references from a set of
|
|||
|
|
“roots”, are deleted.</p><p>The following suboperations may be specified:</p><div class="variablelist"><dl class="variablelist"><dt><span class="term"><code class="option">--print-roots</code></span></dt><dd><p>This operation prints on standard output the set
|
|||
|
|
of roots used by the garbage collector. What constitutes a root
|
|||
|
|
is described in <a class="xref" href="#ssec-gc-roots" title="11.1. Garbage Collector Roots">Section 11.1, “Garbage Collector Roots”</a>.</p></dd><dt><span class="term"><code class="option">--print-live</code></span></dt><dd><p>This operation prints on standard output the set
|
|||
|
|
of “live” store paths, which are all the store paths reachable
|
|||
|
|
from the roots. Live paths should never be deleted, since that
|
|||
|
|
would break consistency — it would become possible that
|
|||
|
|
applications are installed that reference things that are no
|
|||
|
|
longer present in the store.</p></dd><dt><span class="term"><code class="option">--print-dead</code></span></dt><dd><p>This operation prints out on standard output the
|
|||
|
|
set of “dead” store paths, which is just the opposite of the set
|
|||
|
|
of live paths: any path in the store that is not live (with
|
|||
|
|
respect to the roots) is dead.</p></dd></dl></div><p>By default, all unreachable paths are deleted. The following
|
|||
|
|
options control what gets deleted and in what order:
|
|||
|
|
|
|||
|
|
</p><div class="variablelist"><dl class="variablelist"><dt><span class="term"><code class="option">--max-freed</code> <em class="replaceable"><code>bytes</code></em></span></dt><dd><p>Keep deleting paths until at least
|
|||
|
|
<em class="replaceable"><code>bytes</code></em> bytes have been deleted, then
|
|||
|
|
stop. The argument <em class="replaceable"><code>bytes</code></em> can be
|
|||
|
|
followed by the multiplicative suffix <code class="literal">K</code>,
|
|||
|
|
<code class="literal">M</code>, <code class="literal">G</code> or
|
|||
|
|
<code class="literal">T</code>, denoting KiB, MiB, GiB or TiB
|
|||
|
|
units.</p></dd></dl></div><p>
|
|||
|
|
|
|||
|
|
</p><p>The behaviour of the collector is also influenced by the <a class="link" href="#conf-keep-outputs"><code class="literal">keep-outputs</code></a>
|
|||
|
|
and <a class="link" href="#conf-keep-derivations"><code class="literal">keep-derivations</code></a>
|
|||
|
|
variables in the Nix configuration file.</p><p>By default, the collector prints the total number of freed bytes
|
|||
|
|
when it finishes (or when it is interrupted). With
|
|||
|
|
<code class="option">--print-dead</code>, it prints the number of bytes that would
|
|||
|
|
be freed.</p></div><div class="refsection"><a id="idm139733299619488"></a><h3>Examples</h3><p>To delete all unreachable paths, just do:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-store --gc
|
|||
|
|
deleting `/nix/store/kq82idx6g0nyzsp2s14gfsc38npai7lf-cairo-1.0.4.tar.gz.drv'
|
|||
|
|
<em class="replaceable"><code>...</code></em>
|
|||
|
|
8825586 bytes freed (8.42 MiB)</pre><p>
|
|||
|
|
|
|||
|
|
</p><p>To delete at least 100 MiBs of unreachable paths:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-store --gc --max-freed $((100 * 1024 * 1024))</pre><p>
|
|||
|
|
|
|||
|
|
</p></div></div><div class="refsection"><a id="idm139733299615968"></a><h2>Operation <code class="option">--delete</code></h2><div class="refsection"><a id="idm139733299615136"></a><h3>Synopsis</h3><div class="cmdsynopsis"><p><code class="command">nix-store</code> <code class="option">--delete</code> [<code class="option">--ignore-liveness</code>] <em class="replaceable"><code>paths</code></em>... </p></div></div><div class="refsection"><a id="idm139733299611216"></a><h3>Description</h3><p>The operation <code class="option">--delete</code> deletes the store paths
|
|||
|
|
<em class="replaceable"><code>paths</code></em> from the Nix store, but only if it is
|
|||
|
|
safe to do so; that is, when the path is not reachable from a root of
|
|||
|
|
the garbage collector. This means that you can only delete paths that
|
|||
|
|
would also be deleted by <code class="literal">nix-store --gc</code>. Thus,
|
|||
|
|
<code class="literal">--delete</code> is a more targeted version of
|
|||
|
|
<code class="literal">--gc</code>.</p><p>With the option <code class="option">--ignore-liveness</code>, reachability
|
|||
|
|
from the roots is ignored. However, the path still won’t be deleted
|
|||
|
|
if there are other paths in the store that refer to it (i.e., depend
|
|||
|
|
on it).</p></div><div class="refsection"><a id="idm139733299606528"></a><h3>Example</h3><pre class="screen">
|
|||
|
|
$ nix-store --delete /nix/store/zq0h41l75vlb4z45kzgjjmsjxvcv1qk7-mesa-6.4
|
|||
|
|
0 bytes freed (0.00 MiB)
|
|||
|
|
error: cannot delete path `/nix/store/zq0h41l75vlb4z45kzgjjmsjxvcv1qk7-mesa-6.4' since it is still alive</pre></div></div><div class="refsection"><a id="refsec-nix-store-query"></a><h2>Operation <code class="option">--query</code></h2><div class="refsection"><a id="idm139733299603504"></a><h3>Synopsis</h3><div class="cmdsynopsis"><p><code class="command">nix-store</code> { <code class="option">--query</code> | <code class="option">-q</code> } { <code class="option">--outputs</code> | <code class="option">--requisites</code> | <code class="option">-R</code> | <code class="option">--references</code> | <code class="option">--referrers</code> | <code class="option">--referrers-closure</code> | <code class="option">--deriver</code> | <code class="option">-d</code> | <code class="option">--graph</code> | <code class="option">--tree</code> | <code class="option">--binding</code> <em class="replaceable"><code>name</code></em> | <code class="option">-b</code> <em class="replaceable"><code>name</code></em> | <code class="option">--hash</code> | <code class="option">--size</code> | <code class="option">--roots</code> } [<code class="option">--use-output</code>] [<code class="option">-u</code>] [<code class="option">--force-realise</code>] [<code class="option">-f</code>] <em class="replaceable"><code>paths</code></em>... </p></div></div><div class="refsection"><a id="idm139733299583008"></a><h3>Description</h3><p>The operation <code class="option">--query</code> displays various bits of
|
|||
|
|
information about the store paths . The queries are described below. At
|
|||
|
|
most one query can be specified. The default query is
|
|||
|
|
<code class="option">--outputs</code>.</p><p>The paths <em class="replaceable"><code>paths</code></em> may also be symlinks
|
|||
|
|
from outside of the Nix store, to the Nix store. In that case, the
|
|||
|
|
query is applied to the target of the symlink.</p></div><div class="refsection"><a id="idm139733299579920"></a><h3>Common query options</h3><div class="variablelist"><dl class="variablelist"><dt><span class="term"><code class="option">--use-output</code>, </span><span class="term"><code class="option">-u</code></span></dt><dd><p>For each argument to the query that is a store
|
|||
|
|
derivation, apply the query to the output path of the derivation
|
|||
|
|
instead.</p></dd><dt><span class="term"><code class="option">--force-realise</code>, </span><span class="term"><code class="option">-f</code></span></dt><dd><p>Realise each argument to the query first (see
|
|||
|
|
<a class="link" href="#rsec-nix-store-realise" title="Operation --realise"><span class="command"><strong>nix-store
|
|||
|
|
--realise</strong></span></a>).</p></dd></dl></div></div><div class="refsection"><a id="nixref-queries"></a><h3>Queries</h3><div class="variablelist"><dl class="variablelist"><dt><span class="term"><code class="option">--outputs</code></span></dt><dd><p>Prints out the <a class="link" href="#gloss-output-path" title="output path">output paths</a> of the store
|
|||
|
|
derivations <em class="replaceable"><code>paths</code></em>. These are the paths
|
|||
|
|
that will be produced when the derivation is
|
|||
|
|
built.</p></dd><dt><span class="term"><code class="option">--requisites</code>, </span><span class="term"><code class="option">-R</code></span></dt><dd><p>Prints out the <a class="link" href="#gloss-closure" title="closure">closure</a> of the store path
|
|||
|
|
<em class="replaceable"><code>paths</code></em>.</p><p>This query has one option:</p><div class="variablelist"><dl class="variablelist"><dt><span class="term"><code class="option">--include-outputs</code></span></dt><dd><p>Also include the output path of store
|
|||
|
|
derivations, and their closures.</p></dd></dl></div><p>This query can be used to implement various kinds of
|
|||
|
|
deployment. A <span class="emphasis"><em>source deployment</em></span> is obtained
|
|||
|
|
by distributing the closure of a store derivation. A
|
|||
|
|
<span class="emphasis"><em>binary deployment</em></span> is obtained by distributing
|
|||
|
|
the closure of an output path. A <span class="emphasis"><em>cache
|
|||
|
|
deployment</em></span> (combined source/binary deployment,
|
|||
|
|
including binaries of build-time-only dependencies) is obtained by
|
|||
|
|
distributing the closure of a store derivation and specifying the
|
|||
|
|
option <code class="option">--include-outputs</code>.</p></dd><dt><span class="term"><code class="option">--references</code></span></dt><dd><p>Prints the set of <a class="link" href="#gloss-reference" title="reference">references</a> of the store paths
|
|||
|
|
<em class="replaceable"><code>paths</code></em>, that is, their immediate
|
|||
|
|
dependencies. (For <span class="emphasis"><em>all</em></span> dependencies, use
|
|||
|
|
<code class="option">--requisites</code>.)</p></dd><dt><span class="term"><code class="option">--referrers</code></span></dt><dd><p>Prints the set of <span class="emphasis"><em>referrers</em></span> of
|
|||
|
|
the store paths <em class="replaceable"><code>paths</code></em>, that is, the
|
|||
|
|
store paths currently existing in the Nix store that refer to one
|
|||
|
|
of <em class="replaceable"><code>paths</code></em>. Note that contrary to the
|
|||
|
|
references, the set of referrers is not constant; it can change as
|
|||
|
|
store paths are added or removed.</p></dd><dt><span class="term"><code class="option">--referrers-closure</code></span></dt><dd><p>Prints the closure of the set of store paths
|
|||
|
|
<em class="replaceable"><code>paths</code></em> under the referrers relation; that
|
|||
|
|
is, all store paths that directly or indirectly refer to one of
|
|||
|
|
<em class="replaceable"><code>paths</code></em>. These are all the path currently
|
|||
|
|
in the Nix store that are dependent on
|
|||
|
|
<em class="replaceable"><code>paths</code></em>.</p></dd><dt><span class="term"><code class="option">--deriver</code>, </span><span class="term"><code class="option">-d</code></span></dt><dd><p>Prints the <a class="link" href="#gloss-deriver" title="deriver">deriver</a> of the store paths
|
|||
|
|
<em class="replaceable"><code>paths</code></em>. If the path has no deriver
|
|||
|
|
(e.g., if it is a source file), or if the deriver is not known
|
|||
|
|
(e.g., in the case of a binary-only deployment), the string
|
|||
|
|
<code class="literal">unknown-deriver</code> is printed.</p></dd><dt><span class="term"><code class="option">--graph</code></span></dt><dd><p>Prints the references graph of the store paths
|
|||
|
|
<em class="replaceable"><code>paths</code></em> in the format of the
|
|||
|
|
<span class="command"><strong>dot</strong></span> tool of AT&T's <a class="link" href="http://www.graphviz.org/" target="_top">Graphviz package</a>.
|
|||
|
|
This can be used to visualise dependency graphs. To obtain a
|
|||
|
|
build-time dependency graph, apply this to a store derivation. To
|
|||
|
|
obtain a runtime dependency graph, apply it to an output
|
|||
|
|
path.</p></dd><dt><span class="term"><code class="option">--tree</code></span></dt><dd><p>Prints the references graph of the store paths
|
|||
|
|
<em class="replaceable"><code>paths</code></em> as a nested ASCII tree.
|
|||
|
|
References are ordered by descending closure size; this tends to
|
|||
|
|
flatten the tree, making it more readable. The query only
|
|||
|
|
recurses into a store path when it is first encountered; this
|
|||
|
|
prevents a blowup of the tree representation of the
|
|||
|
|
graph.</p></dd><dt><span class="term"><code class="option">--graphml</code></span></dt><dd><p>Prints the references graph of the store paths
|
|||
|
|
<em class="replaceable"><code>paths</code></em> in the <a class="link" href="http://graphml.graphdrawing.org/" target="_top">GraphML</a> file format.
|
|||
|
|
This can be used to visualise dependency graphs. To obtain a
|
|||
|
|
build-time dependency graph, apply this to a store derivation. To
|
|||
|
|
obtain a runtime dependency graph, apply it to an output
|
|||
|
|
path.</p></dd><dt><span class="term"><code class="option">--binding</code> <em class="replaceable"><code>name</code></em>, </span><span class="term"><code class="option">-b</code> <em class="replaceable"><code>name</code></em></span></dt><dd><p>Prints the value of the attribute
|
|||
|
|
<em class="replaceable"><code>name</code></em> (i.e., environment variable) of
|
|||
|
|
the store derivations <em class="replaceable"><code>paths</code></em>. It is an
|
|||
|
|
error for a derivation to not have the specified
|
|||
|
|
attribute.</p></dd><dt><span class="term"><code class="option">--hash</code></span></dt><dd><p>Prints the SHA-256 hash of the contents of the
|
|||
|
|
store paths <em class="replaceable"><code>paths</code></em> (that is, the hash of
|
|||
|
|
the output of <span class="command"><strong>nix-store --dump</strong></span> on the given
|
|||
|
|
paths). Since the hash is stored in the Nix database, this is a
|
|||
|
|
fast operation.</p></dd><dt><span class="term"><code class="option">--size</code></span></dt><dd><p>Prints the size in bytes of the contents of the
|
|||
|
|
store paths <em class="replaceable"><code>paths</code></em> — to be precise, the
|
|||
|
|
size of the output of <span class="command"><strong>nix-store --dump</strong></span> on the
|
|||
|
|
given paths. Note that the actual disk space required by the
|
|||
|
|
store paths may be higher, especially on filesystems with large
|
|||
|
|
cluster sizes.</p></dd><dt><span class="term"><code class="option">--roots</code></span></dt><dd><p>Prints the garbage collector roots that point,
|
|||
|
|
directly or indirectly, at the store paths
|
|||
|
|
<em class="replaceable"><code>paths</code></em>.</p></dd></dl></div></div><div class="refsection"><a id="idm139733299531008"></a><h3>Examples</h3><p>Print the closure (runtime dependencies) of the
|
|||
|
|
<span class="command"><strong>svn</strong></span> program in the current user environment:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-store -qR $(which svn)
|
|||
|
|
/nix/store/5mbglq5ldqld8sj57273aljwkfvj22mc-subversion-1.1.4
|
|||
|
|
/nix/store/9lz9yc6zgmc0vlqmn2ipcpkjlmbi51vv-glibc-2.3.4
|
|||
|
|
<em class="replaceable"><code>...</code></em></pre><p>
|
|||
|
|
|
|||
|
|
</p><p>Print the build-time dependencies of <span class="command"><strong>svn</strong></span>:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-store -qR $(nix-store -qd $(which svn))
|
|||
|
|
/nix/store/02iizgn86m42q905rddvg4ja975bk2i4-grep-2.5.1.tar.bz2.drv
|
|||
|
|
/nix/store/07a2bzxmzwz5hp58nf03pahrv2ygwgs3-gcc-wrapper.sh
|
|||
|
|
/nix/store/0ma7c9wsbaxahwwl04gbw3fcd806ski4-glibc-2.3.4.drv
|
|||
|
|
<em class="replaceable"><code>... lots of other paths ...</code></em></pre><p>
|
|||
|
|
|
|||
|
|
The difference with the previous example is that we ask the closure of
|
|||
|
|
the derivation (<code class="option">-qd</code>), not the closure of the output
|
|||
|
|
path that contains <span class="command"><strong>svn</strong></span>.</p><p>Show the build-time dependencies as a tree:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-store -q --tree $(nix-store -qd $(which svn))
|
|||
|
|
/nix/store/7i5082kfb6yjbqdbiwdhhza0am2xvh6c-subversion-1.1.4.drv
|
|||
|
|
+---/nix/store/d8afh10z72n8l1cr5w42366abiblgn54-builder.sh
|
|||
|
|
+---/nix/store/fmzxmpjx2lh849ph0l36snfj9zdibw67-bash-3.0.drv
|
|||
|
|
| +---/nix/store/570hmhmx3v57605cqg9yfvvyh0nnb8k8-bash
|
|||
|
|
| +---/nix/store/p3srsbd8dx44v2pg6nbnszab5mcwx03v-builder.sh
|
|||
|
|
<em class="replaceable"><code>...</code></em></pre><p>
|
|||
|
|
|
|||
|
|
</p><p>Show all paths that depend on the same OpenSSL library as
|
|||
|
|
<span class="command"><strong>svn</strong></span>:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-store -q --referrers $(nix-store -q --binding openssl $(nix-store -qd $(which svn)))
|
|||
|
|
/nix/store/23ny9l9wixx21632y2wi4p585qhva1q8-sylpheed-1.0.0
|
|||
|
|
/nix/store/5mbglq5ldqld8sj57273aljwkfvj22mc-subversion-1.1.4
|
|||
|
|
/nix/store/dpmvp969yhdqs7lm2r1a3gng7pyq6vy4-subversion-1.1.3
|
|||
|
|
/nix/store/l51240xqsgg8a7yrbqdx1rfzyv6l26fx-lynx-2.8.5</pre><p>
|
|||
|
|
|
|||
|
|
</p><p>Show all paths that directly or indirectly depend on the Glibc
|
|||
|
|
(C library) used by <span class="command"><strong>svn</strong></span>:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-store -q --referrers-closure $(ldd $(which svn) | grep /libc.so | awk '{print $3}')
|
|||
|
|
/nix/store/034a6h4vpz9kds5r6kzb9lhh81mscw43-libgnomeprintui-2.8.2
|
|||
|
|
/nix/store/15l3yi0d45prm7a82pcrknxdh6nzmxza-gawk-3.1.4
|
|||
|
|
<em class="replaceable"><code>...</code></em></pre><p>
|
|||
|
|
|
|||
|
|
Note that <span class="command"><strong>ldd</strong></span> is a command that prints out the
|
|||
|
|
dynamic libraries used by an ELF executable.</p><p>Make a picture of the runtime dependency graph of the current
|
|||
|
|
user environment:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-store -q --graph ~/.nix-profile | dot -Tps > graph.ps
|
|||
|
|
$ gv graph.ps</pre><p>
|
|||
|
|
|
|||
|
|
</p><p>Show every garbage collector root that points to a store path
|
|||
|
|
that depends on <span class="command"><strong>svn</strong></span>:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-store -q --roots $(which svn)
|
|||
|
|
/nix/var/nix/profiles/default-81-link
|
|||
|
|
/nix/var/nix/profiles/default-82-link
|
|||
|
|
/nix/var/nix/profiles/per-user/eelco/profile-97-link
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
</p></div></div><div class="refsection"><a id="idm139733299516176"></a><h2>Operation <code class="option">--add</code></h2><div class="refsection"><a id="idm139733299515344"></a><h3>Synopsis</h3><div class="cmdsynopsis"><p><code class="command">nix-store</code> <code class="option">--add</code> <em class="replaceable"><code>paths</code></em>... </p></div></div><div class="refsection"><a id="idm139733299511968"></a><h3>Description</h3><p>The operation <code class="option">--add</code> adds the specified paths to
|
|||
|
|
the Nix store. It prints the resulting paths in the Nix store on
|
|||
|
|
standard output.</p></div><div class="refsection"><a id="idm139733299510336"></a><h3>Example</h3><pre class="screen">
|
|||
|
|
$ nix-store --add ./foo.c
|
|||
|
|
/nix/store/m7lrha58ph6rcnv109yzx1nk1cj7k7zf-foo.c</pre></div></div><div class="refsection"><a id="idm139733299508688"></a><h2>Operation <code class="option">--add-fixed</code></h2><div class="refsection"><a id="idm139733299507856"></a><h3>Synopsis</h3><div class="cmdsynopsis"><p><code class="command">nix-store</code> [<code class="option">--recursive</code>] <code class="option">--add-fixed</code> <em class="replaceable"><code>algorithm</code></em> <em class="replaceable"><code>paths</code></em>... </p></div></div><div class="refsection"><a id="idm139733299503120"></a><h3>Description</h3><p>The operation <code class="option">--add-fixed</code> adds the specified paths to
|
|||
|
|
the Nix store. Unlike <code class="option">--add</code> paths are registered using the
|
|||
|
|
specified hashing algorithm, resulting in the same output path as a fixed-output
|
|||
|
|
derivation. This can be used for sources that are not available from a public
|
|||
|
|
url or broke since the download expression was written.
|
|||
|
|
</p><p>This operation has the following options:
|
|||
|
|
|
|||
|
|
</p><div class="variablelist"><dl class="variablelist"><dt><span class="term"><code class="option">--recursive</code></span></dt><dd><p>
|
|||
|
|
Use recursive instead of flat hashing mode, used when adding directories
|
|||
|
|
to the store.
|
|||
|
|
</p></dd></dl></div><p>
|
|||
|
|
|
|||
|
|
</p></div><div class="refsection"><a id="idm139733299498592"></a><h3>Example</h3><pre class="screen">
|
|||
|
|
$ nix-store --add-fixed sha256 ./hello-2.10.tar.gz
|
|||
|
|
/nix/store/3x7dwzq014bblazs7kq20p9hyzz0qh8g-hello-2.10.tar.gz</pre></div></div><div class="refsection"><a id="refsec-nix-store-verify"></a><h2>Operation <code class="option">--verify</code></h2><div class="refsection"><a id="idm139733299495712"></a><h3>Synopsis</h3><div class="cmdsynopsis"><p><code class="command">nix-store</code> <code class="option">--verify</code> [<code class="option">--check-contents</code>] [<code class="option">--repair</code>]</p></div></div><div class="refsection"><a id="idm139733299492208"></a><h3>Description</h3><p>The operation <code class="option">--verify</code> verifies the internal
|
|||
|
|
consistency of the Nix database, and the consistency between the Nix
|
|||
|
|
database and the Nix store. Any inconsistencies encountered are
|
|||
|
|
automatically repaired. Inconsistencies are generally the result of
|
|||
|
|
the Nix store or database being modified by non-Nix tools, or of bugs
|
|||
|
|
in Nix itself.</p><p>This operation has the following options:
|
|||
|
|
|
|||
|
|
</p><div class="variablelist"><dl class="variablelist"><dt><span class="term"><code class="option">--check-contents</code></span></dt><dd><p>Checks that the contents of every valid store path
|
|||
|
|
has not been altered by computing a SHA-256 hash of the contents
|
|||
|
|
and comparing it with the hash stored in the Nix database at build
|
|||
|
|
time. Paths that have been modified are printed out. For large
|
|||
|
|
stores, <code class="option">--check-contents</code> is obviously quite
|
|||
|
|
slow.</p></dd><dt><span class="term"><code class="option">--repair</code></span></dt><dd><p>If any valid path is missing from the store, or
|
|||
|
|
(if <code class="option">--check-contents</code> is given) the contents of a
|
|||
|
|
valid path has been modified, then try to repair the path by
|
|||
|
|
redownloading it. See <span class="command"><strong>nix-store --repair-path</strong></span>
|
|||
|
|
for details.</p></dd></dl></div><p>
|
|||
|
|
|
|||
|
|
</p></div></div><div class="refsection"><a id="idm139733299484592"></a><h2>Operation <code class="option">--verify-path</code></h2><div class="refsection"><a id="idm139733299483760"></a><h3>Synopsis</h3><div class="cmdsynopsis"><p><code class="command">nix-store</code> <code class="option">--verify-path</code> <em class="replaceable"><code>paths</code></em>... </p></div></div><div class="refsection"><a id="idm139733299480256"></a><h3>Description</h3><p>The operation <code class="option">--verify-path</code> compares the
|
|||
|
|
contents of the given store paths to their cryptographic hashes stored
|
|||
|
|
in Nix’s database. For every changed path, it prints a warning
|
|||
|
|
message. The exit status is 0 if no path has changed, and 1
|
|||
|
|
otherwise.</p></div><div class="refsection"><a id="idm139733299478288"></a><h3>Example</h3><p>To verify the integrity of the <span class="command"><strong>svn</strong></span> command and all its dependencies:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-store --verify-path $(nix-store -qR $(which svn))
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
</p></div></div><div class="refsection"><a id="idm139733299475792"></a><h2>Operation <code class="option">--repair-path</code></h2><div class="refsection"><a id="idm139733299474960"></a><h3>Synopsis</h3><div class="cmdsynopsis"><p><code class="command">nix-store</code> <code class="option">--repair-path</code> <em class="replaceable"><code>paths</code></em>... </p></div></div><div class="refsection"><a id="idm139733299471456"></a><h3>Description</h3><p>The operation <code class="option">--repair-path</code> attempts to
|
|||
|
|
“repair” the specified paths by redownloading them using the available
|
|||
|
|
substituters. If no substitutes are available, then repair is not
|
|||
|
|
possible.</p><div class="warning"><h3 class="title">Warning</h3><p>During repair, there is a very small time window during
|
|||
|
|
which the old path (if it exists) is moved out of the way and replaced
|
|||
|
|
with the new path. If repair is interrupted in between, then the
|
|||
|
|
system may be left in a broken state (e.g., if the path contains a
|
|||
|
|
critical system component like the GNU C Library).</p></div></div><div class="refsection"><a id="idm139733299468768"></a><h3>Example</h3><pre class="screen">
|
|||
|
|
$ nix-store --verify-path /nix/store/dj7a81wsm1ijwwpkks3725661h3263p5-glibc-2.13
|
|||
|
|
path `/nix/store/dj7a81wsm1ijwwpkks3725661h3263p5-glibc-2.13' was modified!
|
|||
|
|
expected hash `2db57715ae90b7e31ff1f2ecb8c12ec1cc43da920efcbe3b22763f36a1861588',
|
|||
|
|
got `481c5aa5483ebc97c20457bb8bca24deea56550d3985cda0027f67fe54b808e4'
|
|||
|
|
|
|||
|
|
$ nix-store --repair-path /nix/store/dj7a81wsm1ijwwpkks3725661h3263p5-glibc-2.13
|
|||
|
|
fetching path `/nix/store/d7a81wsm1ijwwpkks3725661h3263p5-glibc-2.13'...
|
|||
|
|
…
|
|||
|
|
</pre></div></div><div class="refsection"><a id="refsec-nix-store-dump"></a><h2>Operation <code class="option">--dump</code></h2><div class="refsection"><a id="idm139733299465056"></a><h3>Synopsis</h3><div class="cmdsynopsis"><p><code class="command">nix-store</code> <code class="option">--dump</code> <em class="replaceable"><code>path</code></em> </p></div></div><div class="refsection"><a id="idm139733299461824"></a><h3>Description</h3><p>The operation <code class="option">--dump</code> produces a NAR (Nix
|
|||
|
|
ARchive) file containing the contents of the file system tree rooted
|
|||
|
|
at <em class="replaceable"><code>path</code></em>. The archive is written to
|
|||
|
|
standard output.</p><p>A NAR archive is like a TAR or Zip archive, but it contains only
|
|||
|
|
the information that Nix considers important. For instance,
|
|||
|
|
timestamps are elided because all files in the Nix store have their
|
|||
|
|
timestamp set to 0 anyway. Likewise, all permissions are left out
|
|||
|
|
except for the execute bit, because all files in the Nix store have
|
|||
|
|
444 or 555 permission.</p><p>Also, a NAR archive is <span class="emphasis"><em>canonical</em></span>, meaning
|
|||
|
|
that “equal” paths always produce the same NAR archive. For instance,
|
|||
|
|
directory entries are always sorted so that the actual on-disk order
|
|||
|
|
doesn’t influence the result. This means that the cryptographic hash
|
|||
|
|
of a NAR dump of a path is usable as a fingerprint of the contents of
|
|||
|
|
the path. Indeed, the hashes of store paths stored in Nix’s database
|
|||
|
|
(see <a class="link" href="#refsec-nix-store-query" title="Operation --query"><code class="literal">nix-store -q
|
|||
|
|
--hash</code></a>) are SHA-256 hashes of the NAR dump of each
|
|||
|
|
store path.</p><p>NAR archives support filenames of unlimited length and 64-bit
|
|||
|
|
file sizes. They can contain regular files, directories, and symbolic
|
|||
|
|
links, but not other types of files (such as device nodes).</p><p>A Nix archive can be unpacked using <code class="literal">nix-store
|
|||
|
|
--restore</code>.</p></div></div><div class="refsection"><a id="idm139733299454672"></a><h2>Operation <code class="option">--restore</code></h2><div class="refsection"><a id="idm139733299453840"></a><h3>Synopsis</h3><div class="cmdsynopsis"><p><code class="command">nix-store</code> <code class="option">--restore</code> <em class="replaceable"><code>path</code></em> </p></div></div><div class="refsection"><a id="idm139733299450608"></a><h3>Description</h3><p>The operation <code class="option">--restore</code> unpacks a NAR archive
|
|||
|
|
to <em class="replaceable"><code>path</code></em>, which must not already exist. The
|
|||
|
|
archive is read from standard input.</p></div></div><div class="refsection"><a id="refsec-nix-store-export"></a><h2>Operation <code class="option">--export</code></h2><div class="refsection"><a id="idm139733299446736"></a><h3>Synopsis</h3><div class="cmdsynopsis"><p><code class="command">nix-store</code> <code class="option">--export</code> <em class="replaceable"><code>paths</code></em>... </p></div></div><div class="refsection"><a id="idm139733299443232"></a><h3>Description</h3><p>The operation <code class="option">--export</code> writes a serialisation
|
|||
|
|
of the specified store paths to standard output in a format that can
|
|||
|
|
be imported into another Nix store with <span class="command"><strong><a class="command" href="#refsec-nix-store-import" title="Operation --import">nix-store --import</a></strong></span>. This
|
|||
|
|
is like <span class="command"><strong><a class="command" href="#refsec-nix-store-dump" title="Operation --dump">nix-store
|
|||
|
|
--dump</a></strong></span>, except that the NAR archive produced by that command
|
|||
|
|
doesn’t contain the necessary meta-information to allow it to be
|
|||
|
|
imported into another Nix store (namely, the set of references of the
|
|||
|
|
path).</p><p>This command does not produce a <span class="emphasis"><em>closure</em></span> of
|
|||
|
|
the specified paths, so if a store path references other store paths
|
|||
|
|
that are missing in the target Nix store, the import will fail. To
|
|||
|
|
copy a whole closure, do something like:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-store --export $(nix-store -qR <em class="replaceable"><code>paths</code></em>) > out</pre><p>
|
|||
|
|
|
|||
|
|
To import the whole closure again, run:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-store --import < out</pre><p>
|
|||
|
|
|
|||
|
|
</p></div></div><div class="refsection"><a id="refsec-nix-store-import"></a><h2>Operation <code class="option">--import</code></h2><div class="refsection"><a id="idm139733299435520"></a><h3>Synopsis</h3><div class="cmdsynopsis"><p><code class="command">nix-store</code> <code class="option">--import</code> </p></div></div><div class="refsection"><a id="idm139733299433104"></a><h3>Description</h3><p>The operation <code class="option">--import</code> reads a serialisation of
|
|||
|
|
a set of store paths produced by <span class="command"><strong><a class="command" href="#refsec-nix-store-export" title="Operation --export">nix-store --export</a></strong></span> from
|
|||
|
|
standard input and adds those store paths to the Nix store. Paths
|
|||
|
|
that already exist in the Nix store are ignored. If a path refers to
|
|||
|
|
another path that doesn’t exist in the Nix store, the import
|
|||
|
|
fails.</p></div></div><div class="refsection"><a id="idm139733299429888"></a><h2>Operation <code class="option">--optimise</code></h2><div class="refsection"><a id="idm139733299429056"></a><h3>Synopsis</h3><div class="cmdsynopsis"><p><code class="command">nix-store</code> <code class="option">--optimise</code> </p></div></div><div class="refsection"><a id="idm139733299426640"></a><h3>Description</h3><p>The operation <code class="option">--optimise</code> reduces Nix store disk
|
|||
|
|
space usage by finding identical files in the store and hard-linking
|
|||
|
|
them to each other. It typically reduces the size of the store by
|
|||
|
|
something like 25-35%. Only regular files and symlinks are
|
|||
|
|
hard-linked in this manner. Files are considered identical when they
|
|||
|
|
have the same NAR archive serialisation: that is, regular files must
|
|||
|
|
have the same contents and permission (executable or non-executable),
|
|||
|
|
and symlinks must have the same contents.</p><p>After completion, or when the command is interrupted, a report
|
|||
|
|
on the achieved savings is printed on standard error.</p><p>Use <code class="option">-vv</code> or <code class="option">-vvv</code> to get some
|
|||
|
|
progress indication.</p></div><div class="refsection"><a id="idm139733299423328"></a><h3>Example</h3><pre class="screen">
|
|||
|
|
$ nix-store --optimise
|
|||
|
|
hashing files in `/nix/store/qhqx7l2f1kmwihc9bnxs7rc159hsxnf3-gcc-4.1.1'
|
|||
|
|
<em class="replaceable"><code>...</code></em>
|
|||
|
|
541838819 bytes (516.74 MiB) freed by hard-linking 54143 files;
|
|||
|
|
there are 114486 files with equal contents out of 215894 files in total
|
|||
|
|
</pre></div></div><div class="refsection"><a id="idm139733299421120"></a><h2>Operation <code class="option">--read-log</code></h2><div class="refsection"><a id="idm139733299420288"></a><h3>Synopsis</h3><div class="cmdsynopsis"><p><code class="command">nix-store</code> { <code class="option">--read-log</code> | <code class="option">-l</code> } <em class="replaceable"><code>paths</code></em>... </p></div></div><div class="refsection"><a id="idm139733299415376"></a><h3>Description</h3><p>The operation <code class="option">--read-log</code> prints the build log
|
|||
|
|
of the specified store paths on standard output. The build log is
|
|||
|
|
whatever the builder of a derivation wrote to standard output and
|
|||
|
|
standard error. If a store path is not a derivation, the deriver of
|
|||
|
|
the store path is used.</p><p>Build logs are kept in
|
|||
|
|
<code class="filename">/nix/var/log/nix/drvs</code>. However, there is no
|
|||
|
|
guarantee that a build log is available for any particular store path.
|
|||
|
|
For instance, if the path was downloaded as a pre-built binary through
|
|||
|
|
a substitute, then the log is unavailable.</p></div><div class="refsection"><a id="idm139733299412560"></a><h3>Example</h3><pre class="screen">
|
|||
|
|
$ nix-store -l $(which ktorrent)
|
|||
|
|
building /nix/store/dhc73pvzpnzxhdgpimsd9sw39di66ph1-ktorrent-2.2.1
|
|||
|
|
unpacking sources
|
|||
|
|
unpacking source archive /nix/store/p8n1jpqs27mgkjw07pb5269717nzf5f8-ktorrent-2.2.1.tar.gz
|
|||
|
|
ktorrent-2.2.1/
|
|||
|
|
ktorrent-2.2.1/NEWS
|
|||
|
|
<em class="replaceable"><code>...</code></em>
|
|||
|
|
</pre></div></div><div class="refsection"><a id="idm139733299410368"></a><h2>Operation <code class="option">--dump-db</code></h2><div class="refsection"><a id="idm139733299409536"></a><h3>Synopsis</h3><div class="cmdsynopsis"><p><code class="command">nix-store</code> <code class="option">--dump-db</code> [<em class="replaceable"><code>paths</code></em>...]</p></div></div><div class="refsection"><a id="idm139733299406304"></a><h3>Description</h3><p>The operation <code class="option">--dump-db</code> writes a dump of the
|
|||
|
|
Nix database to standard output. It can be loaded into an empty Nix
|
|||
|
|
store using <code class="option">--load-db</code>. This is useful for making
|
|||
|
|
backups and when migrating to different database schemas.</p><p>By default, <code class="option">--dump-db</code> will dump the entire Nix
|
|||
|
|
database. When one or more store paths is passed, only the subset of
|
|||
|
|
the Nix database for those store paths is dumped. As with
|
|||
|
|
<code class="option">--export</code>, the user is responsible for passing all the
|
|||
|
|
store paths for a closure. See <code class="option">--export</code> for an
|
|||
|
|
example.</p></div></div><div class="refsection"><a id="idm139733299401712"></a><h2>Operation <code class="option">--load-db</code></h2><div class="refsection"><a id="idm139733299400880"></a><h3>Synopsis</h3><div class="cmdsynopsis"><p><code class="command">nix-store</code> <code class="option">--load-db</code> </p></div></div><div class="refsection"><a id="idm139733299398464"></a><h3>Description</h3><p>The operation <code class="option">--load-db</code> reads a dump of the Nix
|
|||
|
|
database created by <code class="option">--dump-db</code> from standard input and
|
|||
|
|
loads it into the Nix database.</p></div></div><div class="refsection"><a id="idm139733299395904"></a><h2>Operation <code class="option">--print-env</code></h2><div class="refsection"><a id="idm139733299395072"></a><h3>Synopsis</h3><div class="cmdsynopsis"><p><code class="command">nix-store</code> <code class="option">--print-env</code> <em class="replaceable"><code>drvpath</code></em> </p></div></div><div class="refsection"><a id="idm139733299391840"></a><h3>Description</h3><p>The operation <code class="option">--print-env</code> prints out the
|
|||
|
|
environment of a derivation in a format that can be evaluated by a
|
|||
|
|
shell. The command line arguments of the builder are placed in the
|
|||
|
|
variable <code class="envar">_args</code>.</p></div><div class="refsection"><a id="idm139733299389744"></a><h3>Example</h3><pre class="screen">
|
|||
|
|
$ nix-store --print-env $(nix-instantiate '<nixpkgs>' -A firefox)
|
|||
|
|
<em class="replaceable"><code>…</code></em>
|
|||
|
|
export src; src='/nix/store/plpj7qrwcz94z2psh6fchsi7s8yihc7k-firefox-12.0.source.tar.bz2'
|
|||
|
|
export stdenv; stdenv='/nix/store/7c8asx3yfrg5dg1gzhzyq2236zfgibnn-stdenv'
|
|||
|
|
export system; system='x86_64-linux'
|
|||
|
|
export _args; _args='-e /nix/store/9krlzvny65gdc8s7kpb6lkx8cd02c25c-default-builder.sh'
|
|||
|
|
</pre></div></div><div class="refsection"><a id="rsec-nix-store-generate-binary-cache-key"></a><h2>Operation <code class="option">--generate-binary-cache-key</code></h2><div class="refsection"><a id="idm139733299386016"></a><h3>Synopsis</h3><div class="cmdsynopsis"><p><code class="command">nix-store</code>
|
|||
|
|
<code class="option">--generate-binary-cache-key</code>
|
|||
|
|
<code class="option">key-name</code>
|
|||
|
|
<code class="option">secret-key-file</code>
|
|||
|
|
<code class="option">public-key-file</code>
|
|||
|
|
</p></div></div><div class="refsection"><a id="idm139733299382080"></a><h3>Description</h3><p>This command generates an <a class="link" href="http://ed25519.cr.yp.to/" target="_top">Ed25519 key pair</a> that can
|
|||
|
|
be used to create a signed binary cache. It takes three mandatory
|
|||
|
|
parameters:
|
|||
|
|
|
|||
|
|
</p><div class="orderedlist"><ol class="orderedlist" type="1"><li class="listitem"><p>A key name, such as
|
|||
|
|
<code class="literal">cache.example.org-1</code>, that is used to look up keys
|
|||
|
|
on the client when it verifies signatures. It can be anything, but
|
|||
|
|
it’s suggested to use the host name of your cache
|
|||
|
|
(e.g. <code class="literal">cache.example.org</code>) with a suffix denoting
|
|||
|
|
the number of the key (to be incremented every time you need to
|
|||
|
|
revoke a key).</p></li><li class="listitem"><p>The file name where the secret key is to be
|
|||
|
|
stored.</p></li><li class="listitem"><p>The file name where the public key is to be
|
|||
|
|
stored.</p></li></ol></div><p>
|
|||
|
|
|
|||
|
|
</p></div></div></div></div><div class="chapter"><div class="titlepage"><div><div><h2 class="title"><a id="ch-utilities"></a>Chapter 23. Utilities</h2></div></div></div><p>This section lists utilities that you can use when you
|
|||
|
|
work with Nix.</p><div class="refentry"><a id="sec-nix-channel"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>nix-channel — manage Nix channels</p></div><div class="refsynopsisdiv"><h2>Synopsis</h2><div class="cmdsynopsis"><p><code class="command">nix-channel</code> { <code class="option">--add</code> <em class="replaceable"><code>url</code></em> [<em class="replaceable"><code>name</code></em>] | <code class="option">--remove</code> <em class="replaceable"><code>name</code></em> | <code class="option">--list</code> | <code class="option">--update</code> [<em class="replaceable"><code>names</code></em>...] | <code class="option">--rollback</code> [<em class="replaceable"><code>generation</code></em>] }</p></div></div><div class="refsection"><a id="idm139733299360672"></a><h2>Description</h2><p>A Nix channel is a mechanism that allows you to automatically
|
|||
|
|
stay up-to-date with a set of pre-built Nix expressions. A Nix
|
|||
|
|
channel is just a URL that points to a place containing a set of Nix
|
|||
|
|
expressions. <span class="phrase">See also <a class="xref" href="#sec-channels" title="Chapter 12. Channels">Chapter 12, <em>Channels</em></a>.</span></p><p>To see the list of official NixOS channels, visit <a class="link" href="https://nixos.org/channels" target="_top">https://nixos.org/channels</a>.</p><p>This command has the following operations:
|
|||
|
|
|
|||
|
|
</p><div class="variablelist"><dl class="variablelist"><dt><span class="term"><code class="option">--add</code> <em class="replaceable"><code>url</code></em> [<em class="replaceable"><code>name</code></em>]</span></dt><dd><p>Adds a channel named
|
|||
|
|
<em class="replaceable"><code>name</code></em> with URL
|
|||
|
|
<em class="replaceable"><code>url</code></em> to the list of subscribed channels.
|
|||
|
|
If <em class="replaceable"><code>name</code></em> is omitted, it defaults to the
|
|||
|
|
last component of <em class="replaceable"><code>url</code></em>, with the
|
|||
|
|
suffixes <code class="literal">-stable</code> or
|
|||
|
|
<code class="literal">-unstable</code> removed.</p></dd><dt><span class="term"><code class="option">--remove</code> <em class="replaceable"><code>name</code></em></span></dt><dd><p>Removes the channel named
|
|||
|
|
<em class="replaceable"><code>name</code></em> from the list of subscribed
|
|||
|
|
channels.</p></dd><dt><span class="term"><code class="option">--list</code></span></dt><dd><p>Prints the names and URLs of all subscribed
|
|||
|
|
channels on standard output.</p></dd><dt><span class="term"><code class="option">--update</code> [<em class="replaceable"><code>names</code></em>…]</span></dt><dd><p>Downloads the Nix expressions of all subscribed
|
|||
|
|
channels (or only those included in
|
|||
|
|
<em class="replaceable"><code>names</code></em> if specified) and makes them the
|
|||
|
|
default for <span class="command"><strong>nix-env</strong></span> operations (by symlinking
|
|||
|
|
them from the directory
|
|||
|
|
<code class="filename">~/.nix-defexpr</code>).</p></dd><dt><span class="term"><code class="option">--rollback</code> [<em class="replaceable"><code>generation</code></em>]</span></dt><dd><p>Reverts the previous call to <span class="command"><strong>nix-channel
|
|||
|
|
--update</strong></span>. Optionally, you can specify a specific channel
|
|||
|
|
generation number to restore.</p></dd></dl></div><p>
|
|||
|
|
|
|||
|
|
</p><p>Note that <code class="option">--add</code> does not automatically perform
|
|||
|
|
an update.</p><p>The list of subscribed channels is stored in
|
|||
|
|
<code class="filename">~/.nix-channels</code>.</p></div><div class="refsection"><a id="idm139733299340240"></a><h2>Examples</h2><p>To subscribe to the Nixpkgs channel and install the GNU Hello package:</p><pre class="screen">
|
|||
|
|
$ nix-channel --add https://nixos.org/channels/nixpkgs-unstable
|
|||
|
|
$ nix-channel --update
|
|||
|
|
$ nix-env -iA nixpkgs.hello</pre><p>You can revert channel updates using <code class="option">--rollback</code>:</p><pre class="screen">
|
|||
|
|
$ nix-instantiate --eval -E '(import <nixpkgs> {}).lib.version'
|
|||
|
|
"14.04.527.0e935f1"
|
|||
|
|
|
|||
|
|
$ nix-channel --rollback
|
|||
|
|
switching from generation 483 to 482
|
|||
|
|
|
|||
|
|
$ nix-instantiate --eval -E '(import <nixpkgs> {}).lib.version'
|
|||
|
|
"14.04.526.dbadfad"
|
|||
|
|
</pre></div><div class="refsection"><a id="idm139733299336912"></a><h2>Files</h2><div class="variablelist"><dl class="variablelist"><dt><span class="term"><code class="filename">/nix/var/nix/profiles/per-user/<em class="replaceable"><code>username</code></em>/channels</code></span></dt><dd><p><span class="command"><strong>nix-channel</strong></span> uses a
|
|||
|
|
<span class="command"><strong>nix-env</strong></span> profile to keep track of previous
|
|||
|
|
versions of the subscribed channels. Every time you run
|
|||
|
|
<span class="command"><strong>nix-channel --update</strong></span>, a new channel generation
|
|||
|
|
(that is, a symlink to the channel Nix expressions in the Nix store)
|
|||
|
|
is created. This enables <span class="command"><strong>nix-channel --rollback</strong></span>
|
|||
|
|
to revert to previous versions.</p></dd><dt><span class="term"><code class="filename">~/.nix-defexpr/channels</code></span></dt><dd><p>This is a symlink to
|
|||
|
|
<code class="filename">/nix/var/nix/profiles/per-user/<em class="replaceable"><code>username</code></em>/channels</code>. It
|
|||
|
|
ensures that <span class="command"><strong>nix-env</strong></span> can find your channels. In
|
|||
|
|
a multi-user installation, you may also have
|
|||
|
|
<code class="filename">~/.nix-defexpr/channels_root</code>, which links to
|
|||
|
|
the channels of the root user.</p></dd></dl></div></div><div class="refsection"><a id="idm139733299328928"></a><h2>Channel format</h2><p>A channel URL should point to a directory containing the
|
|||
|
|
following files:</p><div class="variablelist"><dl class="variablelist"><dt><span class="term"><code class="filename">nixexprs.tar.xz</code></span></dt><dd><p>A tarball containing Nix expressions and files
|
|||
|
|
referenced by them (such as build scripts and patches). At the
|
|||
|
|
top level, the tarball should contain a single directory. That
|
|||
|
|
directory must contain a file <code class="filename">default.nix</code>
|
|||
|
|
that serves as the channel’s “entry point”.</p></dd></dl></div></div></div><div class="refentry"><div class="refentry.separator"><hr /></div><a id="sec-nix-collect-garbage"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>nix-collect-garbage — delete unreachable store paths</p></div><div class="refsynopsisdiv"><h2>Synopsis</h2><div class="cmdsynopsis"><p><code class="command">nix-collect-garbage</code> [<code class="option">--delete-old</code>] [<code class="option">-d</code>] [<code class="option">--delete-older-than</code> <em class="replaceable"><code>period</code></em>] [<code class="option">--max-freed</code> <em class="replaceable"><code>bytes</code></em>] [<code class="option">--dry-run</code>]</p></div></div><div class="refsection"><a id="idm139733299315776"></a><h2>Description</h2><p>The command <span class="command"><strong>nix-collect-garbage</strong></span> is mostly an
|
|||
|
|
alias of <a class="link" href="#rsec-nix-store-gc" title="Operation --gc"><span class="command"><strong>nix-store
|
|||
|
|
--gc</strong></span></a>, that is, it deletes all unreachable paths in
|
|||
|
|
the Nix store to clean up your system. However, it provides two
|
|||
|
|
additional options: <code class="option">-d</code> (<code class="option">--delete-old</code>),
|
|||
|
|
which deletes all old generations of all profiles in
|
|||
|
|
<code class="filename">/nix/var/nix/profiles</code> by invoking
|
|||
|
|
<code class="literal">nix-env --delete-generations old</code> on all profiles
|
|||
|
|
(of course, this makes rollbacks to previous configurations
|
|||
|
|
impossible); and
|
|||
|
|
<code class="option">--delete-older-than</code> <em class="replaceable"><code>period</code></em>,
|
|||
|
|
where period is a value such as <code class="literal">30d</code>, which deletes
|
|||
|
|
all generations older than the specified number of days in all profiles
|
|||
|
|
in <code class="filename">/nix/var/nix/profiles</code> (except for the generations
|
|||
|
|
that were active at that point in time).
|
|||
|
|
</p></div><div class="refsection"><a id="idm139733299309536"></a><h2>Example</h2><p>To delete from the Nix store everything that is not used by the
|
|||
|
|
current generations of each profile, do
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-collect-garbage -d</pre><p>
|
|||
|
|
|
|||
|
|
</p></div></div><div class="refentry"><div class="refentry.separator"><hr /></div><a id="sec-nix-copy-closure"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>nix-copy-closure — copy a closure to or from a remote machine via SSH</p></div><div class="refsynopsisdiv"><h2>Synopsis</h2><div class="cmdsynopsis"><p><code class="command">nix-copy-closure</code> [ <code class="option">--to</code> | <code class="option">--from</code> ] [<code class="option">--gzip</code>] [<code class="option">--include-outputs</code>] [ <code class="option">--use-substitutes</code> | <code class="option">-s</code> ] [<code class="option">-v</code>]
|
|||
|
|
<em class="replaceable"><code>user@</code></em><em class="replaceable"><code>machine</code></em>
|
|||
|
|
<em class="replaceable"><code>paths</code></em> </p></div></div><div class="refsection"><a id="idm139733299294048"></a><h2>Description</h2><p><span class="command"><strong>nix-copy-closure</strong></span> gives you an easy and
|
|||
|
|
efficient way to exchange software between machines. Given one or
|
|||
|
|
more Nix store <em class="replaceable"><code>paths</code></em> on the local
|
|||
|
|
machine, <span class="command"><strong>nix-copy-closure</strong></span> computes the closure of
|
|||
|
|
those paths (i.e. all their dependencies in the Nix store), and copies
|
|||
|
|
all paths in the closure to the remote machine via the
|
|||
|
|
<span class="command"><strong>ssh</strong></span> (Secure Shell) command. With the
|
|||
|
|
<code class="option">--from</code>, the direction is reversed:
|
|||
|
|
the closure of <em class="replaceable"><code>paths</code></em> on a remote machine is
|
|||
|
|
copied to the Nix store on the local machine.</p><p>This command is efficient because it only sends the store paths
|
|||
|
|
that are missing on the target machine.</p><p>Since <span class="command"><strong>nix-copy-closure</strong></span> calls
|
|||
|
|
<span class="command"><strong>ssh</strong></span>, you may be asked to type in the appropriate
|
|||
|
|
password or passphrase. In fact, you may be asked
|
|||
|
|
<span class="emphasis"><em>twice</em></span> because <span class="command"><strong>nix-copy-closure</strong></span>
|
|||
|
|
currently connects twice to the remote machine, first to get the set
|
|||
|
|
of paths missing on the target machine, and second to send the dump of
|
|||
|
|
those paths. If this bothers you, use
|
|||
|
|
<span class="command"><strong>ssh-agent</strong></span>.</p><div class="refsection"><a id="idm139733299286896"></a><h3>Options</h3><div class="variablelist"><dl class="variablelist"><dt><span class="term"><code class="option">--to</code></span></dt><dd><p>Copy the closure of
|
|||
|
|
<em class="replaceable"><code>paths</code></em> from the local Nix store to the
|
|||
|
|
Nix store on <em class="replaceable"><code>machine</code></em>. This is the
|
|||
|
|
default.</p></dd><dt><span class="term"><code class="option">--from</code></span></dt><dd><p>Copy the closure of
|
|||
|
|
<em class="replaceable"><code>paths</code></em> from the Nix store on
|
|||
|
|
<em class="replaceable"><code>machine</code></em> to the local Nix
|
|||
|
|
store.</p></dd><dt><span class="term"><code class="option">--gzip</code></span></dt><dd><p>Enable compression of the SSH
|
|||
|
|
connection.</p></dd><dt><span class="term"><code class="option">--include-outputs</code></span></dt><dd><p>Also copy the outputs of store derivations
|
|||
|
|
included in the closure.</p></dd><dt><span class="term"><code class="option">--use-substitutes</code> / <code class="option">-s</code></span></dt><dd><p>Attempt to download missing paths on the target
|
|||
|
|
machine using Nix’s substitute mechanism. Any paths that cannot
|
|||
|
|
be substituted on the target are still copied normally from the
|
|||
|
|
source. This is useful, for instance, if the connection between
|
|||
|
|
the source and target machine is slow, but the connection between
|
|||
|
|
the target machine and <code class="literal">nixos.org</code> (the default
|
|||
|
|
binary cache server) is fast.</p></dd><dt><span class="term"><code class="option">-v</code></span></dt><dd><p>Show verbose output.</p></dd></dl></div></div><div class="refsection"><a id="idm139733299274272"></a><h3>Environment variables</h3><div class="variablelist"><dl class="variablelist"><dt><span class="term"><code class="envar">NIX_SSHOPTS</code></span></dt><dd><p>Additional options to be passed to
|
|||
|
|
<span class="command"><strong>ssh</strong></span> on the command line.</p></dd></dl></div></div><div class="refsection"><a id="idm139733299271440"></a><h3>Examples</h3><p>Copy Firefox with all its dependencies to a remote machine:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-copy-closure --to alice@itchy.labs $(type -tP firefox)</pre><p>
|
|||
|
|
|
|||
|
|
</p><p>Copy Subversion from a remote machine and then install it into a
|
|||
|
|
user environment:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-copy-closure --from alice@itchy.labs \
|
|||
|
|
/nix/store/0dj0503hjxy5mbwlafv1rsbdiyx1gkdy-subversion-1.4.4
|
|||
|
|
$ nix-env -i /nix/store/0dj0503hjxy5mbwlafv1rsbdiyx1gkdy-subversion-1.4.4
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
</p></div></div></div><div class="refentry"><div class="refentry.separator"><hr /></div><a id="sec-nix-daemon"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>nix-daemon — Nix multi-user support daemon</p></div><div class="refsynopsisdiv"><h2>Synopsis</h2><div class="cmdsynopsis"><p><code class="command">nix-daemon</code> </p></div></div><div class="refsection"><a id="idm139733299262736"></a><h2>Description</h2><p>The Nix daemon is necessary in multi-user Nix installations. It
|
|||
|
|
performs build actions and other operations on the Nix store on behalf
|
|||
|
|
of unprivileged users.</p></div></div><div class="refentry"><div class="refentry.separator"><hr /></div><a id="sec-nix-hash"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>nix-hash — compute the cryptographic hash of a path</p></div><div class="refsynopsisdiv"><h2>Synopsis</h2><div class="cmdsynopsis"><p><code class="command">nix-hash</code> [<code class="option">--flat</code>] [<code class="option">--base32</code>] [<code class="option">--truncate</code>] [<code class="option">--type</code> <em class="replaceable"><code>hashAlgo</code></em>] <em class="replaceable"><code>path</code></em>... </p></div><div class="cmdsynopsis"><p><code class="command">nix-hash</code> <code class="option">--to-base16</code> <em class="replaceable"><code>hash</code></em>... </p></div><div class="cmdsynopsis"><p><code class="command">nix-hash</code> <code class="option">--to-base32</code> <em class="replaceable"><code>hash</code></em>... </p></div></div><div class="refsection"><a id="idm139733299246496"></a><h2>Description</h2><p>The command <span class="command"><strong>nix-hash</strong></span> computes the
|
|||
|
|
cryptographic hash of the contents of each
|
|||
|
|
<em class="replaceable"><code>path</code></em> and prints it on standard output. By
|
|||
|
|
default, it computes an MD5 hash, but other hash algorithms are
|
|||
|
|
available as well. The hash is printed in hexadecimal. To generate
|
|||
|
|
the same hash as <span class="command"><strong>nix-prefetch-url</strong></span> you have to
|
|||
|
|
specify multiple arguments, see below for an example.</p><p>The hash is computed over a <span class="emphasis"><em>serialisation</em></span>
|
|||
|
|
of each path: a dump of the file system tree rooted at the path. This
|
|||
|
|
allows directories and symlinks to be hashed as well as regular files.
|
|||
|
|
The dump is in the <span class="emphasis"><em>NAR format</em></span> produced by <a class="link" href="#refsec-nix-store-dump" title="Operation --dump"><span class="command"><strong>nix-store</strong></span>
|
|||
|
|
<code class="option">--dump</code></a>. Thus, <code class="literal">nix-hash
|
|||
|
|
<em class="replaceable"><code>path</code></em></code> yields the same
|
|||
|
|
cryptographic hash as <code class="literal">nix-store --dump
|
|||
|
|
<em class="replaceable"><code>path</code></em> | md5sum</code>.</p></div><div class="refsection"><a id="idm139733299239440"></a><h2>Options</h2><div class="variablelist"><dl class="variablelist"><dt><span class="term"><code class="option">--flat</code></span></dt><dd><p>Print the cryptographic hash of the contents of
|
|||
|
|
each regular file <em class="replaceable"><code>path</code></em>. That is, do
|
|||
|
|
not compute the hash over the dump of
|
|||
|
|
<em class="replaceable"><code>path</code></em>. The result is identical to that
|
|||
|
|
produced by the GNU commands <span class="command"><strong>md5sum</strong></span> and
|
|||
|
|
<span class="command"><strong>sha1sum</strong></span>.</p></dd><dt><span class="term"><code class="option">--base32</code></span></dt><dd><p>Print the hash in a base-32 representation rather
|
|||
|
|
than hexadecimal. This base-32 representation is more compact and
|
|||
|
|
can be used in Nix expressions (such as in calls to
|
|||
|
|
<code class="function">fetchurl</code>).</p></dd><dt><span class="term"><code class="option">--truncate</code></span></dt><dd><p>Truncate hashes longer than 160 bits (such as
|
|||
|
|
SHA-256) to 160 bits.</p></dd><dt><span class="term"><code class="option">--type</code> <em class="replaceable"><code>hashAlgo</code></em></span></dt><dd><p>Use the specified cryptographic hash algorithm,
|
|||
|
|
which can be one of <code class="literal">md5</code>,
|
|||
|
|
<code class="literal">sha1</code>, and
|
|||
|
|
<code class="literal">sha256</code>.</p></dd><dt><span class="term"><code class="option">--to-base16</code></span></dt><dd><p>Don’t hash anything, but convert the base-32 hash
|
|||
|
|
representation <em class="replaceable"><code>hash</code></em> to
|
|||
|
|
hexadecimal.</p></dd><dt><span class="term"><code class="option">--to-base32</code></span></dt><dd><p>Don’t hash anything, but convert the hexadecimal
|
|||
|
|
hash representation <em class="replaceable"><code>hash</code></em> to
|
|||
|
|
base-32.</p></dd></dl></div></div><div class="refsection"><a id="idm139733299224832"></a><h2>Examples</h2><p>Computing the same hash as <span class="command"><strong>nix-prefetch-url</strong></span>:
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-prefetch-url file://<(echo test)
|
|||
|
|
1lkgqb6fclns49861dwk9rzb6xnfkxbpws74mxnx01z9qyv1pjpj
|
|||
|
|
$ nix-hash --type sha256 --flat --base32 <(echo test)
|
|||
|
|
1lkgqb6fclns49861dwk9rzb6xnfkxbpws74mxnx01z9qyv1pjpj
|
|||
|
|
</pre><p>
|
|||
|
|
</p><p>Computing hashes:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ mkdir test
|
|||
|
|
$ echo "hello" > test/world
|
|||
|
|
|
|||
|
|
$ nix-hash test/ <em class="lineannotation"><span class="lineannotation">(MD5 hash; default)</span></em>
|
|||
|
|
8179d3caeff1869b5ba1744e5a245c04
|
|||
|
|
|
|||
|
|
$ nix-store --dump test/ | md5sum <em class="lineannotation"><span class="lineannotation">(for comparison)</span></em>
|
|||
|
|
8179d3caeff1869b5ba1744e5a245c04 -
|
|||
|
|
|
|||
|
|
$ nix-hash --type sha1 test/
|
|||
|
|
e4fd8ba5f7bbeaea5ace89fe10255536cd60dab6
|
|||
|
|
|
|||
|
|
$ nix-hash --type sha1 --base32 test/
|
|||
|
|
nvd61k9nalji1zl9rrdfmsmvyyjqpzg4
|
|||
|
|
|
|||
|
|
$ nix-hash --type sha256 --flat test/
|
|||
|
|
error: reading file `test/': Is a directory
|
|||
|
|
|
|||
|
|
$ nix-hash --type sha256 --flat test/world
|
|||
|
|
5891b5b522d5df086d0ff0b110fbd9d21bb4fc7163af34d08286a2e846f6be03</pre><p>
|
|||
|
|
|
|||
|
|
</p><p>Converting between hexadecimal and base-32:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-hash --type sha1 --to-base32 e4fd8ba5f7bbeaea5ace89fe10255536cd60dab6
|
|||
|
|
nvd61k9nalji1zl9rrdfmsmvyyjqpzg4
|
|||
|
|
|
|||
|
|
$ nix-hash --type sha1 --to-base16 nvd61k9nalji1zl9rrdfmsmvyyjqpzg4
|
|||
|
|
e4fd8ba5f7bbeaea5ace89fe10255536cd60dab6</pre><p>
|
|||
|
|
|
|||
|
|
</p></div></div><div class="refentry"><div class="refentry.separator"><hr /></div><a id="sec-nix-instantiate"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>nix-instantiate — instantiate store derivations from Nix expressions</p></div><div class="refsynopsisdiv"><h2>Synopsis</h2><div class="cmdsynopsis"><p><code class="command">nix-instantiate</code> [ <code class="option">--parse</code> |
|
|||
|
|
<code class="option">--eval</code>
|
|||
|
|
[<code class="option">--strict</code>]
|
|||
|
|
[<code class="option">--json</code>]
|
|||
|
|
[<code class="option">--xml</code>]
|
|||
|
|
] [<code class="option">--read-write-mode</code>] [<code class="option">--arg</code> <em class="replaceable"><code>name</code></em> <em class="replaceable"><code>value</code></em>] [
|
|||
|
|
{ <code class="option">--attr</code> | <code class="option">-A</code> }
|
|||
|
|
<em class="replaceable"><code>attrPath</code></em>
|
|||
|
|
] [<code class="option">--add-root</code> <em class="replaceable"><code>path</code></em>] [<code class="option">--indirect</code>] [ <code class="option">--expr</code> | <code class="option">-E</code> ] <em class="replaceable"><code>files</code></em>... </p></div><div class="cmdsynopsis"><p><code class="command">nix-instantiate</code> <code class="option">--find-file</code> <em class="replaceable"><code>files</code></em>... </p></div></div><div class="refsection"><a id="idm139733299196816"></a><h2>Description</h2><p>The command <span class="command"><strong>nix-instantiate</strong></span> generates <a class="link" href="#gloss-derivation" title="derivation">store derivations</a> from (high-level)
|
|||
|
|
Nix expressions. It evaluates the Nix expressions in each of
|
|||
|
|
<em class="replaceable"><code>files</code></em> (which defaults to
|
|||
|
|
<em class="replaceable"><code>./default.nix</code></em>). Each top-level expression
|
|||
|
|
should evaluate to a derivation, a list of derivations, or a set of
|
|||
|
|
derivations. The paths of the resulting store derivations are printed
|
|||
|
|
on standard output.</p><p>If <em class="replaceable"><code>files</code></em> is the character
|
|||
|
|
<code class="literal">-</code>, then a Nix expression will be read from standard
|
|||
|
|
input.</p><p>See also <a class="xref" href="#sec-common-options" title="Chapter 20. Common Options">Chapter 20, <em>Common Options</em></a> for a list of common options.</p></div><div class="refsection"><a id="idm139733299190864"></a><h2>Options</h2><div class="variablelist"><dl class="variablelist"><dt><span class="term"><code class="option">--add-root</code> <em class="replaceable"><code>path</code></em>, </span><span class="term"><code class="option">--indirect</code></span></dt><dd><p>See the <a class="link" href="#opt-add-root">corresponding
|
|||
|
|
options</a> in <span class="command"><strong>nix-store</strong></span>.</p></dd><dt><span class="term"><code class="option">--parse</code></span></dt><dd><p>Just parse the input files, and print their
|
|||
|
|
abstract syntax trees on standard output in ATerm
|
|||
|
|
format.</p></dd><dt><span class="term"><code class="option">--eval</code></span></dt><dd><p>Just parse and evaluate the input files, and print
|
|||
|
|
the resulting values on standard output. No instantiation of
|
|||
|
|
store derivations takes place.</p></dd><dt><span class="term"><code class="option">--find-file</code></span></dt><dd><p>Look up the given files in Nix’s search path (as
|
|||
|
|
specified by the <code class="envar"><a class="envar" href="#env-NIX_PATH">NIX_PATH</a></code>
|
|||
|
|
environment variable). If found, print the corresponding absolute
|
|||
|
|
paths on standard output. For instance, if
|
|||
|
|
<code class="envar">NIX_PATH</code> is
|
|||
|
|
<code class="literal">nixpkgs=/home/alice/nixpkgs</code>, then
|
|||
|
|
<code class="literal">nix-instantiate --find-file nixpkgs/default.nix</code>
|
|||
|
|
will print
|
|||
|
|
<code class="literal">/home/alice/nixpkgs/default.nix</code>.</p></dd><dt><span class="term"><code class="option">--strict</code></span></dt><dd><p>When used with <code class="option">--eval</code>,
|
|||
|
|
recursively evaluate list elements and attributes. Normally, such
|
|||
|
|
sub-expressions are left unevaluated (since the Nix expression
|
|||
|
|
language is lazy).</p><div class="warning"><h3 class="title">Warning</h3><p>This option can cause non-termination, because lazy
|
|||
|
|
data structures can be infinitely large.</p></div></dd><dt><span class="term"><code class="option">--json</code></span></dt><dd><p>When used with <code class="option">--eval</code>, print the resulting
|
|||
|
|
value as an JSON representation of the abstract syntax tree rather
|
|||
|
|
than as an ATerm.</p></dd><dt><span class="term"><code class="option">--xml</code></span></dt><dd><p>When used with <code class="option">--eval</code>, print the resulting
|
|||
|
|
value as an XML representation of the abstract syntax tree rather than as
|
|||
|
|
an ATerm. The schema is the same as that used by the <a class="link" href="#builtin-toXML"><code class="function">toXML</code> built-in</a>.
|
|||
|
|
</p></dd><dt><span class="term"><code class="option">--read-write-mode</code></span></dt><dd><p>When used with <code class="option">--eval</code>, perform
|
|||
|
|
evaluation in read/write mode so nix language features that
|
|||
|
|
require it will still work (at the cost of needing to do
|
|||
|
|
instantiation of every evaluated derivation). If this option is
|
|||
|
|
not enabled, there may be uninstantiated store paths in the final
|
|||
|
|
output.</p></dd></dl></div></div><div class="refsection"><a id="idm139733299169472"></a><h2>Examples</h2><p>Instantiating store derivations from a Nix expression, and
|
|||
|
|
building them using <span class="command"><strong>nix-store</strong></span>:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-instantiate test.nix <em class="lineannotation"><span class="lineannotation">(instantiate)</span></em>
|
|||
|
|
/nix/store/cigxbmvy6dzix98dxxh9b6shg7ar5bvs-perl-BerkeleyDB-0.26.drv
|
|||
|
|
|
|||
|
|
$ nix-store -r $(nix-instantiate test.nix) <em class="lineannotation"><span class="lineannotation">(build)</span></em>
|
|||
|
|
<em class="replaceable"><code>...</code></em>
|
|||
|
|
/nix/store/qhqk4n8ci095g3sdp93x7rgwyh9rdvgk-perl-BerkeleyDB-0.26 <em class="lineannotation"><span class="lineannotation">(output path)</span></em>
|
|||
|
|
|
|||
|
|
$ ls -l /nix/store/qhqk4n8ci095g3sdp93x7rgwyh9rdvgk-perl-BerkeleyDB-0.26
|
|||
|
|
dr-xr-xr-x 2 eelco users 4096 1970-01-01 01:00 lib
|
|||
|
|
...</pre><p>
|
|||
|
|
|
|||
|
|
</p><p>You can also give a Nix expression on the command line:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-instantiate -E 'with import <nixpkgs> { }; hello'
|
|||
|
|
/nix/store/j8s4zyv75a724q38cb0r87rlczaiag4y-hello-2.8.drv
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
This is equivalent to:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-instantiate '<nixpkgs>' -A hello
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
</p><p>Parsing and evaluating Nix expressions:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-instantiate --parse -E '1 + 2'
|
|||
|
|
1 + 2
|
|||
|
|
|
|||
|
|
$ nix-instantiate --eval -E '1 + 2'
|
|||
|
|
3
|
|||
|
|
|
|||
|
|
$ nix-instantiate --eval --xml -E '1 + 2'
|
|||
|
|
<?xml version='1.0' encoding='utf-8'?>
|
|||
|
|
<expr>
|
|||
|
|
<int value="3" />
|
|||
|
|
</expr></pre><p>
|
|||
|
|
|
|||
|
|
</p><p>The difference between non-strict and strict evaluation:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-instantiate --eval --xml -E 'rec { x = "foo"; y = x; }'
|
|||
|
|
<em class="replaceable"><code>...</code></em>
|
|||
|
|
<attr name="x">
|
|||
|
|
<string value="foo" />
|
|||
|
|
</attr>
|
|||
|
|
<attr name="y">
|
|||
|
|
<unevaluated />
|
|||
|
|
</attr>
|
|||
|
|
<em class="replaceable"><code>...</code></em></pre><p>
|
|||
|
|
|
|||
|
|
Note that <code class="varname">y</code> is left unevaluated (the XML
|
|||
|
|
representation doesn’t attempt to show non-normal forms).
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-instantiate --eval --xml --strict -E 'rec { x = "foo"; y = x; }'
|
|||
|
|
<em class="replaceable"><code>...</code></em>
|
|||
|
|
<attr name="x">
|
|||
|
|
<string value="foo" />
|
|||
|
|
</attr>
|
|||
|
|
<attr name="y">
|
|||
|
|
<string value="foo" />
|
|||
|
|
</attr>
|
|||
|
|
<em class="replaceable"><code>...</code></em></pre><p>
|
|||
|
|
|
|||
|
|
</p></div></div><div class="refentry"><div class="refentry.separator"><hr /></div><a id="sec-nix-prefetch-url"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>nix-prefetch-url — copy a file from a URL into the store and print its hash</p></div><div class="refsynopsisdiv"><h2>Synopsis</h2><div class="cmdsynopsis"><p><code class="command">nix-prefetch-url</code> [<code class="option">--version</code>] [<code class="option">--type</code> <em class="replaceable"><code>hashAlgo</code></em>] [<code class="option">--print-path</code>] [<code class="option">--unpack</code>] [<code class="option">--name</code> <em class="replaceable"><code>name</code></em>] <em class="replaceable"><code>url</code></em> [<em class="replaceable"><code>hash</code></em>]</p></div></div><div class="refsection"><a id="idm139733299148080"></a><h2>Description</h2><p>The command <span class="command"><strong>nix-prefetch-url</strong></span> downloads the
|
|||
|
|
file referenced by the URL <em class="replaceable"><code>url</code></em>, prints its
|
|||
|
|
cryptographic hash, and copies it into the Nix store. The file name
|
|||
|
|
in the store is
|
|||
|
|
<code class="filename"><em class="replaceable"><code>hash</code></em>-<em class="replaceable"><code>baseName</code></em></code>,
|
|||
|
|
where <em class="replaceable"><code>baseName</code></em> is everything following the
|
|||
|
|
final slash in <em class="replaceable"><code>url</code></em>.</p><p>This command is just a convenience for Nix expression writers.
|
|||
|
|
Often a Nix expression fetches some source distribution from the
|
|||
|
|
network using the <code class="literal">fetchurl</code> expression contained in
|
|||
|
|
Nixpkgs. However, <code class="literal">fetchurl</code> requires a
|
|||
|
|
cryptographic hash. If you don't know the hash, you would have to
|
|||
|
|
download the file first, and then <code class="literal">fetchurl</code> would
|
|||
|
|
download it again when you build your Nix expression. Since
|
|||
|
|
<code class="literal">fetchurl</code> uses the same name for the downloaded file
|
|||
|
|
as <span class="command"><strong>nix-prefetch-url</strong></span>, the redundant download can be
|
|||
|
|
avoided.</p><p>If <em class="replaceable"><code>hash</code></em> is specified, then a download
|
|||
|
|
is not performed if the Nix store already contains a file with the
|
|||
|
|
same hash and base name. Otherwise, the file is downloaded, and an
|
|||
|
|
error is signaled if the actual hash of the file does not match the
|
|||
|
|
specified hash.</p><p>This command prints the hash on standard output. Additionally,
|
|||
|
|
if the option <code class="option">--print-path</code> is used, the path of the
|
|||
|
|
downloaded file in the Nix store is also printed.</p></div><div class="refsection"><a id="idm139733299139072"></a><h2>Options</h2><div class="variablelist"><dl class="variablelist"><dt><span class="term"><code class="option">--type</code> <em class="replaceable"><code>hashAlgo</code></em></span></dt><dd><p>Use the specified cryptographic hash algorithm,
|
|||
|
|
which can be one of <code class="literal">md5</code>,
|
|||
|
|
<code class="literal">sha1</code>, and
|
|||
|
|
<code class="literal">sha256</code>.</p></dd><dt><span class="term"><code class="option">--print-path</code></span></dt><dd><p>Print the store path of the downloaded file on
|
|||
|
|
standard output.</p></dd><dt><span class="term"><code class="option">--unpack</code></span></dt><dd><p>Unpack the archive (which must be a tarball or zip
|
|||
|
|
file) and add the result to the Nix store. The resulting hash can
|
|||
|
|
be used with functions such as Nixpkgs’s
|
|||
|
|
<code class="varname">fetchzip</code> or
|
|||
|
|
<code class="varname">fetchFromGitHub</code>.</p></dd><dt><span class="term"><code class="option">--name</code> <em class="replaceable"><code>name</code></em></span></dt><dd><p>Override the name of the file in the Nix store. By
|
|||
|
|
default, this is
|
|||
|
|
<code class="literal"><em class="replaceable"><code>hash</code></em>-<em class="replaceable"><code>basename</code></em></code>,
|
|||
|
|
where <em class="replaceable"><code>basename</code></em> is the last component of
|
|||
|
|
<em class="replaceable"><code>url</code></em>. Overriding the name is necessary
|
|||
|
|
when <em class="replaceable"><code>basename</code></em> contains characters that
|
|||
|
|
are not allowed in Nix store paths.</p></dd></dl></div></div><div class="refsection"><a id="idm139733299126752"></a><h2>Examples</h2><pre class="screen">
|
|||
|
|
$ nix-prefetch-url ftp://ftp.gnu.org/pub/gnu/hello/hello-2.10.tar.gz
|
|||
|
|
0ssi1wpaf7plaswqqjwigppsg5fyh99vdlb9kzl7c9lng89ndq1i
|
|||
|
|
|
|||
|
|
$ nix-prefetch-url --print-path mirror://gnu/hello/hello-2.10.tar.gz
|
|||
|
|
0ssi1wpaf7plaswqqjwigppsg5fyh99vdlb9kzl7c9lng89ndq1i
|
|||
|
|
/nix/store/3x7dwzq014bblazs7kq20p9hyzz0qh8g-hello-2.10.tar.gz
|
|||
|
|
|
|||
|
|
$ nix-prefetch-url --unpack --print-path https://github.com/NixOS/patchelf/archive/0.8.tar.gz
|
|||
|
|
079agjlv0hrv7fxnx9ngipx14gyncbkllxrp9cccnh3a50fxcmy7
|
|||
|
|
/nix/store/19zrmhm3m40xxaw81c8cqm6aljgrnwj2-0.8.tar.gz
|
|||
|
|
</pre></div></div></div><div class="chapter"><div class="titlepage"><div><div><h2 class="title"><a id="ch-files"></a>Chapter 24. Files</h2></div></div></div><p>This section lists configuration files that you can use when you
|
|||
|
|
work with Nix.</p><div class="refentry"><a id="sec-conf-file"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>nix.conf — Nix configuration file</p></div><div class="refsection"><a id="idm139733299118992"></a><h2>Description</h2><p>By default Nix reads settings from the following places:</p><p>The system-wide configuration file
|
|||
|
|
<code class="filename"><em class="replaceable"><code>sysconfdir</code></em>/nix/nix.conf</code>
|
|||
|
|
(i.e. <code class="filename">/etc/nix/nix.conf</code> on most systems), or
|
|||
|
|
<code class="filename">$NIX_CONF_DIR/nix.conf</code> if
|
|||
|
|
<code class="envar">NIX_CONF_DIR</code> is set. Values loaded in this file are not forwarded to the Nix daemon. The
|
|||
|
|
client assumes that the daemon has already loaded them.
|
|||
|
|
</p><p>User-specific configuration files:</p><p>
|
|||
|
|
If <code class="envar">NIX_USER_CONF_FILES</code> is set, then each path separated by
|
|||
|
|
<code class="literal">:</code> will be loaded in reverse order.
|
|||
|
|
</p><p>
|
|||
|
|
Otherwise it will look for <code class="filename">nix/nix.conf</code> files in
|
|||
|
|
<code class="envar">XDG_CONFIG_DIRS</code> and <code class="envar">XDG_CONFIG_HOME</code>.
|
|||
|
|
|
|||
|
|
The default location is <code class="filename">$HOME/.config/nix.conf</code> if
|
|||
|
|
those environment variables are unset.
|
|||
|
|
</p><p>The configuration files consist of
|
|||
|
|
<code class="literal"><em class="replaceable"><code>name</code></em> =
|
|||
|
|
<em class="replaceable"><code>value</code></em></code> pairs, one per line. Other
|
|||
|
|
files can be included with a line like <code class="literal">include
|
|||
|
|
<em class="replaceable"><code>path</code></em></code>, where
|
|||
|
|
<em class="replaceable"><code>path</code></em> is interpreted relative to the current
|
|||
|
|
conf file and a missing file is an error unless
|
|||
|
|
<code class="literal">!include</code> is used instead.
|
|||
|
|
Comments start with a <code class="literal">#</code> character. Here is an
|
|||
|
|
example configuration file:</p><pre class="programlisting">
|
|||
|
|
keep-outputs = true # Nice for developers
|
|||
|
|
keep-derivations = true # Idem
|
|||
|
|
</pre><p>You can override settings on the command line using the
|
|||
|
|
<code class="option">--option</code> flag, e.g. <code class="literal">--option keep-outputs
|
|||
|
|
false</code>.</p><p>The following settings are currently available:
|
|||
|
|
|
|||
|
|
</p><div class="variablelist"><dl class="variablelist"><dt><a id="conf-allowed-uris"></a><span class="term"><code class="literal">allowed-uris</code></span></dt><dd><p>A list of URI prefixes to which access is allowed in
|
|||
|
|
restricted evaluation mode. For example, when set to
|
|||
|
|
<code class="literal">https://github.com/NixOS</code>, builtin functions
|
|||
|
|
such as <code class="function">fetchGit</code> are allowed to access
|
|||
|
|
<code class="literal">https://github.com/NixOS/patchelf.git</code>.</p></dd><dt><a id="conf-allow-import-from-derivation"></a><span class="term"><code class="literal">allow-import-from-derivation</code></span></dt><dd><p>By default, Nix allows you to <code class="function">import</code> from a derivation,
|
|||
|
|
allowing building at evaluation time. With this option set to false, Nix will throw an error
|
|||
|
|
when evaluating an expression that uses this feature, allowing users to ensure their evaluation
|
|||
|
|
will not require any builds to take place.</p></dd><dt><a id="conf-allow-new-privileges"></a><span class="term"><code class="literal">allow-new-privileges</code></span></dt><dd><p>(Linux-specific.) By default, builders on Linux
|
|||
|
|
cannot acquire new privileges by calling setuid/setgid programs or
|
|||
|
|
programs that have file capabilities. For example, programs such
|
|||
|
|
as <span class="command"><strong>sudo</strong></span> or <span class="command"><strong>ping</strong></span> will
|
|||
|
|
fail. (Note that in sandbox builds, no such programs are available
|
|||
|
|
unless you bind-mount them into the sandbox via the
|
|||
|
|
<code class="option">sandbox-paths</code> option.) You can allow the
|
|||
|
|
use of such programs by enabling this option. This is impure and
|
|||
|
|
usually undesirable, but may be useful in certain scenarios
|
|||
|
|
(e.g. to spin up containers or set up userspace network interfaces
|
|||
|
|
in tests).</p></dd><dt><a id="conf-allowed-users"></a><span class="term"><code class="literal">allowed-users</code></span></dt><dd><p>A list of names of users (separated by whitespace) that
|
|||
|
|
are allowed to connect to the Nix daemon. As with the
|
|||
|
|
<code class="option">trusted-users</code> option, you can specify groups by
|
|||
|
|
prefixing them with <code class="literal">@</code>. Also, you can allow
|
|||
|
|
all users by specifying <code class="literal">*</code>. The default is
|
|||
|
|
<code class="literal">*</code>.</p><p>Note that trusted users are always allowed to connect.</p></dd><dt><a id="conf-auto-optimise-store"></a><span class="term"><code class="literal">auto-optimise-store</code></span></dt><dd><p>If set to <code class="literal">true</code>, Nix
|
|||
|
|
automatically detects files in the store that have identical
|
|||
|
|
contents, and replaces them with hard links to a single copy.
|
|||
|
|
This saves disk space. If set to <code class="literal">false</code> (the
|
|||
|
|
default), you can still run <span class="command"><strong>nix-store
|
|||
|
|
--optimise</strong></span> to get rid of duplicate
|
|||
|
|
files.</p></dd><dt><a id="conf-builders"></a><span class="term"><code class="literal">builders</code></span></dt><dd><p>A list of machines on which to perform builds. <span class="phrase">See <a class="xref" href="#chap-distributed-builds" title="Chapter 16. Remote Builds">Chapter 16, <em>Remote Builds</em></a> for details.</span></p></dd><dt><a id="conf-builders-use-substitutes"></a><span class="term"><code class="literal">builders-use-substitutes</code></span></dt><dd><p>If set to <code class="literal">true</code>, Nix will instruct
|
|||
|
|
remote build machines to use their own binary substitutes if available. In
|
|||
|
|
practical terms, this means that remote hosts will fetch as many build
|
|||
|
|
dependencies as possible from their own substitutes (e.g, from
|
|||
|
|
<code class="literal">cache.nixos.org</code>), instead of waiting for this host to
|
|||
|
|
upload them all. This can drastically reduce build times if the network
|
|||
|
|
connection between this computer and the remote build host is slow. Defaults
|
|||
|
|
to <code class="literal">false</code>.</p></dd><dt><a id="conf-build-users-group"></a><span class="term"><code class="literal">build-users-group</code></span></dt><dd><p>This options specifies the Unix group containing
|
|||
|
|
the Nix build user accounts. In multi-user Nix installations,
|
|||
|
|
builds should not be performed by the Nix account since that would
|
|||
|
|
allow users to arbitrarily modify the Nix store and database by
|
|||
|
|
supplying specially crafted builders; and they cannot be performed
|
|||
|
|
by the calling user since that would allow him/her to influence
|
|||
|
|
the build result.</p><p>Therefore, if this option is non-empty and specifies a valid
|
|||
|
|
group, builds will be performed under the user accounts that are a
|
|||
|
|
member of the group specified here (as listed in
|
|||
|
|
<code class="filename">/etc/group</code>). Those user accounts should not
|
|||
|
|
be used for any other purpose!</p><p>Nix will never run two builds under the same user account at
|
|||
|
|
the same time. This is to prevent an obvious security hole: a
|
|||
|
|
malicious user writing a Nix expression that modifies the build
|
|||
|
|
result of a legitimate Nix expression being built by another user.
|
|||
|
|
Therefore it is good to have as many Nix build user accounts as
|
|||
|
|
you can spare. (Remember: uids are cheap.)</p><p>The build users should have permission to create files in
|
|||
|
|
the Nix store, but not delete them. Therefore,
|
|||
|
|
<code class="filename">/nix/store</code> should be owned by the Nix
|
|||
|
|
account, its group should be the group specified here, and its
|
|||
|
|
mode should be <code class="literal">1775</code>.</p><p>If the build users group is empty, builds will be performed
|
|||
|
|
under the uid of the Nix process (that is, the uid of the caller
|
|||
|
|
if <code class="envar">NIX_REMOTE</code> is empty, the uid under which the Nix
|
|||
|
|
daemon runs if <code class="envar">NIX_REMOTE</code> is
|
|||
|
|
<code class="literal">daemon</code>). Obviously, this should not be used in
|
|||
|
|
multi-user settings with untrusted users.</p></dd><dt><a id="conf-compress-build-log"></a><span class="term"><code class="literal">compress-build-log</code></span></dt><dd><p>If set to <code class="literal">true</code> (the default),
|
|||
|
|
build logs written to <code class="filename">/nix/var/log/nix/drvs</code>
|
|||
|
|
will be compressed on the fly using bzip2. Otherwise, they will
|
|||
|
|
not be compressed.</p></dd><dt><a id="conf-connect-timeout"></a><span class="term"><code class="literal">connect-timeout</code></span></dt><dd><p>The timeout (in seconds) for establishing connections in
|
|||
|
|
the binary cache substituter. It corresponds to
|
|||
|
|
<span class="command"><strong>curl</strong></span>’s <code class="option">--connect-timeout</code>
|
|||
|
|
option.</p></dd><dt><a id="conf-cores"></a><span class="term"><code class="literal">cores</code></span></dt><dd><p>Sets the value of the
|
|||
|
|
<code class="envar">NIX_BUILD_CORES</code> environment variable in the
|
|||
|
|
invocation of builders. Builders can use this variable at their
|
|||
|
|
discretion to control the maximum amount of parallelism. For
|
|||
|
|
instance, in Nixpkgs, if the derivation attribute
|
|||
|
|
<code class="varname">enableParallelBuilding</code> is set to
|
|||
|
|
<code class="literal">true</code>, the builder passes the
|
|||
|
|
<code class="option">-j<em class="replaceable"><code>N</code></em></code> flag to GNU Make.
|
|||
|
|
It can be overridden using the <code class="option"><a class="option" href="#opt-cores">--cores</a></code> command line switch and
|
|||
|
|
defaults to <code class="literal">1</code>. The value <code class="literal">0</code>
|
|||
|
|
means that the builder should use all available CPU cores in the
|
|||
|
|
system.</p><p>See also <a class="xref" href="#chap-tuning-cores-and-jobs" title="Chapter 17. Tuning Cores and Jobs">Chapter 17, <em>Tuning Cores and Jobs</em></a>.</p></dd><dt><a id="conf-diff-hook"></a><span class="term"><code class="literal">diff-hook</code></span></dt><dd><p>
|
|||
|
|
Absolute path to an executable capable of diffing build results.
|
|||
|
|
The hook executes if <a class="xref" href="#conf-run-diff-hook"><code class="literal">run-diff-hook</code></a> is
|
|||
|
|
true, and the output of a build is known to not be the same.
|
|||
|
|
This program is not executed to determine if two results are the
|
|||
|
|
same.
|
|||
|
|
</p><p>
|
|||
|
|
The diff hook is executed by the same user and group who ran the
|
|||
|
|
build. However, the diff hook does not have write access to the
|
|||
|
|
store path just built.
|
|||
|
|
</p><p>The diff hook program receives three parameters:</p><div class="orderedlist"><ol class="orderedlist" type="1"><li class="listitem"><p>
|
|||
|
|
A path to the previous build's results
|
|||
|
|
</p></li><li class="listitem"><p>
|
|||
|
|
A path to the current build's results
|
|||
|
|
</p></li><li class="listitem"><p>
|
|||
|
|
The path to the build's derivation
|
|||
|
|
</p></li><li class="listitem"><p>
|
|||
|
|
The path to the build's scratch directory. This directory
|
|||
|
|
will exist only if the build was run with
|
|||
|
|
<code class="option">--keep-failed</code>.
|
|||
|
|
</p></li></ol></div><p>
|
|||
|
|
The stderr and stdout output from the diff hook will not be
|
|||
|
|
displayed to the user. Instead, it will print to the nix-daemon's
|
|||
|
|
log.
|
|||
|
|
</p><p>When using the Nix daemon, <code class="literal">diff-hook</code> must
|
|||
|
|
be set in the <code class="filename">nix.conf</code> configuration file, and
|
|||
|
|
cannot be passed at the command line.
|
|||
|
|
</p></dd><dt><a id="conf-enforce-determinism"></a><span class="term"><code class="literal">enforce-determinism</code></span></dt><dd><p>See <a class="xref" href="#conf-repeat"><code class="literal">repeat</code></a>.</p></dd><dt><a id="conf-extra-sandbox-paths"></a><span class="term"><code class="literal">extra-sandbox-paths</code></span></dt><dd><p>A list of additional paths appended to
|
|||
|
|
<code class="option">sandbox-paths</code>. Useful if you want to extend
|
|||
|
|
its default value.</p></dd><dt><a id="conf-extra-platforms"></a><span class="term"><code class="literal">extra-platforms</code></span></dt><dd><p>Platforms other than the native one which
|
|||
|
|
this machine is capable of building for. This can be useful for
|
|||
|
|
supporting additional architectures on compatible machines:
|
|||
|
|
i686-linux can be built on x86_64-linux machines (and the default
|
|||
|
|
for this setting reflects this); armv7 is backwards-compatible with
|
|||
|
|
armv6 and armv5tel; some aarch64 machines can also natively run
|
|||
|
|
32-bit ARM code; and qemu-user may be used to support non-native
|
|||
|
|
platforms (though this may be slow and buggy). Most values for this
|
|||
|
|
are not enabled by default because build systems will often
|
|||
|
|
misdetect the target platform and generate incompatible code, so you
|
|||
|
|
may wish to cross-check the results of using this option against
|
|||
|
|
proper natively-built versions of your
|
|||
|
|
derivations.</p></dd><dt><a id="conf-extra-substituters"></a><span class="term"><code class="literal">extra-substituters</code></span></dt><dd><p>Additional binary caches appended to those
|
|||
|
|
specified in <code class="option">substituters</code>. When used by
|
|||
|
|
unprivileged users, untrusted substituters (i.e. those not listed
|
|||
|
|
in <code class="option">trusted-substituters</code>) are silently
|
|||
|
|
ignored.</p></dd><dt><a id="conf-fallback"></a><span class="term"><code class="literal">fallback</code></span></dt><dd><p>If set to <code class="literal">true</code>, Nix will fall
|
|||
|
|
back to building from source if a binary substitute fails. This
|
|||
|
|
is equivalent to the <code class="option">--fallback</code> flag. The
|
|||
|
|
default is <code class="literal">false</code>.</p></dd><dt><a id="conf-fsync-metadata"></a><span class="term"><code class="literal">fsync-metadata</code></span></dt><dd><p>If set to <code class="literal">true</code>, changes to the
|
|||
|
|
Nix store metadata (in <code class="filename">/nix/var/nix/db</code>) are
|
|||
|
|
synchronously flushed to disk. This improves robustness in case
|
|||
|
|
of system crashes, but reduces performance. The default is
|
|||
|
|
<code class="literal">true</code>.</p></dd><dt><a id="conf-hashed-mirrors"></a><span class="term"><code class="literal">hashed-mirrors</code></span></dt><dd><p>A list of web servers used by
|
|||
|
|
<code class="function">builtins.fetchurl</code> to obtain files by hash.
|
|||
|
|
Given a hash type <em class="replaceable"><code>ht</code></em> and a base-16 hash
|
|||
|
|
<em class="replaceable"><code>h</code></em>, Nix will try to download the file
|
|||
|
|
from
|
|||
|
|
<code class="literal">hashed-mirror/<em class="replaceable"><code>ht</code></em>/<em class="replaceable"><code>h</code></em></code>.
|
|||
|
|
This allows files to be downloaded even if they have disappeared
|
|||
|
|
from their original URI. For example, given the hashed mirror
|
|||
|
|
<code class="literal">http://tarballs.example.com/</code>, when building the
|
|||
|
|
derivation
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
builtins.fetchurl {
|
|||
|
|
url = "https://example.org/foo-1.2.3.tar.xz";
|
|||
|
|
sha256 = "2c26b46b68ffc68ff99b453c1d30413413422d706483bfa0f98a5e886266e7ae";
|
|||
|
|
}
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
Nix will attempt to download this file from
|
|||
|
|
<code class="literal">http://tarballs.example.com/sha256/2c26b46b68ffc68ff99b453c1d30413413422d706483bfa0f98a5e886266e7ae</code>
|
|||
|
|
first. If it is not available there, if will try the original URI.</p></dd><dt><a id="conf-http-connections"></a><span class="term"><code class="literal">http-connections</code></span></dt><dd><p>The maximum number of parallel TCP connections
|
|||
|
|
used to fetch files from binary caches and by other downloads. It
|
|||
|
|
defaults to 25. 0 means no limit.</p></dd><dt><a id="conf-keep-build-log"></a><span class="term"><code class="literal">keep-build-log</code></span></dt><dd><p>If set to <code class="literal">true</code> (the default),
|
|||
|
|
Nix will write the build log of a derivation (i.e. the standard
|
|||
|
|
output and error of its builder) to the directory
|
|||
|
|
<code class="filename">/nix/var/log/nix/drvs</code>. The build log can be
|
|||
|
|
retrieved using the command <span class="command"><strong>nix-store -l
|
|||
|
|
<em class="replaceable"><code>path</code></em></strong></span>.</p></dd><dt><a id="conf-keep-derivations"></a><span class="term"><code class="literal">keep-derivations</code></span></dt><dd><p>If <code class="literal">true</code> (default), the garbage
|
|||
|
|
collector will keep the derivations from which non-garbage store
|
|||
|
|
paths were built. If <code class="literal">false</code>, they will be
|
|||
|
|
deleted unless explicitly registered as a root (or reachable from
|
|||
|
|
other roots).</p><p>Keeping derivation around is useful for querying and
|
|||
|
|
traceability (e.g., it allows you to ask with what dependencies or
|
|||
|
|
options a store path was built), so by default this option is on.
|
|||
|
|
Turn it off to save a bit of disk space (or a lot if
|
|||
|
|
<code class="literal">keep-outputs</code> is also turned on).</p></dd><dt><a id="conf-keep-env-derivations"></a><span class="term"><code class="literal">keep-env-derivations</code></span></dt><dd><p>If <code class="literal">false</code> (default), derivations
|
|||
|
|
are not stored in Nix user environments. That is, the derivations of
|
|||
|
|
any build-time-only dependencies may be garbage-collected.</p><p>If <code class="literal">true</code>, when you add a Nix derivation to
|
|||
|
|
a user environment, the path of the derivation is stored in the
|
|||
|
|
user environment. Thus, the derivation will not be
|
|||
|
|
garbage-collected until the user environment generation is deleted
|
|||
|
|
(<span class="command"><strong>nix-env --delete-generations</strong></span>). To prevent
|
|||
|
|
build-time-only dependencies from being collected, you should also
|
|||
|
|
turn on <code class="literal">keep-outputs</code>.</p><p>The difference between this option and
|
|||
|
|
<code class="literal">keep-derivations</code> is that this one is
|
|||
|
|
“sticky”: it applies to any user environment created while this
|
|||
|
|
option was enabled, while <code class="literal">keep-derivations</code>
|
|||
|
|
only applies at the moment the garbage collector is
|
|||
|
|
run.</p></dd><dt><a id="conf-keep-outputs"></a><span class="term"><code class="literal">keep-outputs</code></span></dt><dd><p>If <code class="literal">true</code>, the garbage collector
|
|||
|
|
will keep the outputs of non-garbage derivations. If
|
|||
|
|
<code class="literal">false</code> (default), outputs will be deleted unless
|
|||
|
|
they are GC roots themselves (or reachable from other roots).</p><p>In general, outputs must be registered as roots separately.
|
|||
|
|
However, even if the output of a derivation is registered as a
|
|||
|
|
root, the collector will still delete store paths that are used
|
|||
|
|
only at build time (e.g., the C compiler, or source tarballs
|
|||
|
|
downloaded from the network). To prevent it from doing so, set
|
|||
|
|
this option to <code class="literal">true</code>.</p></dd><dt><a id="conf-max-build-log-size"></a><span class="term"><code class="literal">max-build-log-size</code></span></dt><dd><p>This option defines the maximum number of bytes that a
|
|||
|
|
builder can write to its stdout/stderr. If the builder exceeds
|
|||
|
|
this limit, it’s killed. A value of <code class="literal">0</code> (the
|
|||
|
|
default) means that there is no limit.</p></dd><dt><a id="conf-max-free"></a><span class="term"><code class="literal">max-free</code></span></dt><dd><p>When a garbage collection is triggered by the
|
|||
|
|
<code class="literal">min-free</code> option, it stops as soon as
|
|||
|
|
<code class="literal">max-free</code> bytes are available. The default is
|
|||
|
|
infinity (i.e. delete all garbage).</p></dd><dt><a id="conf-max-jobs"></a><span class="term"><code class="literal">max-jobs</code></span></dt><dd><p>This option defines the maximum number of jobs
|
|||
|
|
that Nix will try to build in parallel. The default is
|
|||
|
|
<code class="literal">1</code>. The special value <code class="literal">auto</code>
|
|||
|
|
causes Nix to use the number of CPUs in your system. <code class="literal">0</code>
|
|||
|
|
is useful when using remote builders to prevent any local builds (except for
|
|||
|
|
<code class="literal">preferLocalBuild</code> derivation attribute which executes locally
|
|||
|
|
regardless). It can be
|
|||
|
|
overridden using the <code class="option"><a class="option" href="#opt-max-jobs">--max-jobs</a></code> (<code class="option">-j</code>)
|
|||
|
|
command line switch.</p><p>See also <a class="xref" href="#chap-tuning-cores-and-jobs" title="Chapter 17. Tuning Cores and Jobs">Chapter 17, <em>Tuning Cores and Jobs</em></a>.</p></dd><dt><a id="conf-max-silent-time"></a><span class="term"><code class="literal">max-silent-time</code></span></dt><dd><p>This option defines the maximum number of seconds that a
|
|||
|
|
builder can go without producing any data on standard output or
|
|||
|
|
standard error. This is useful (for instance in an automated
|
|||
|
|
build system) to catch builds that are stuck in an infinite
|
|||
|
|
loop, or to catch remote builds that are hanging due to network
|
|||
|
|
problems. It can be overridden using the <code class="option"><a class="option" href="#opt-max-silent-time">--max-silent-time</a></code> command
|
|||
|
|
line switch.</p><p>The value <code class="literal">0</code> means that there is no
|
|||
|
|
timeout. This is also the default.</p></dd><dt><a id="conf-min-free"></a><span class="term"><code class="literal">min-free</code></span></dt><dd><p>When free disk space in <code class="filename">/nix/store</code>
|
|||
|
|
drops below <code class="literal">min-free</code> during a build, Nix
|
|||
|
|
performs a garbage-collection until <code class="literal">max-free</code>
|
|||
|
|
bytes are available or there is no more garbage. A value of
|
|||
|
|
<code class="literal">0</code> (the default) disables this feature.</p></dd><dt><a id="conf-narinfo-cache-negative-ttl"></a><span class="term"><code class="literal">narinfo-cache-negative-ttl</code></span></dt><dd><p>The TTL in seconds for negative lookups. If a store path is
|
|||
|
|
queried from a substituter but was not found, there will be a
|
|||
|
|
negative lookup cached in the local disk cache database for the
|
|||
|
|
specified duration.</p></dd><dt><a id="conf-narinfo-cache-positive-ttl"></a><span class="term"><code class="literal">narinfo-cache-positive-ttl</code></span></dt><dd><p>The TTL in seconds for positive lookups. If a store path is
|
|||
|
|
queried from a substituter, the result of the query will be cached
|
|||
|
|
in the local disk cache database including some of the NAR
|
|||
|
|
metadata. The default TTL is a month, setting a shorter TTL for
|
|||
|
|
positive lookups can be useful for binary caches that have
|
|||
|
|
frequent garbage collection, in which case having a more frequent
|
|||
|
|
cache invalidation would prevent trying to pull the path again and
|
|||
|
|
failing with a hash mismatch if the build isn't reproducible.
|
|||
|
|
</p></dd><dt><a id="conf-netrc-file"></a><span class="term"><code class="literal">netrc-file</code></span></dt><dd><p>If set to an absolute path to a <code class="filename">netrc</code>
|
|||
|
|
file, Nix will use the HTTP authentication credentials in this file when
|
|||
|
|
trying to download from a remote host through HTTP or HTTPS. Defaults to
|
|||
|
|
<code class="filename">$NIX_CONF_DIR/netrc</code>.</p><p>The <code class="filename">netrc</code> file consists of a list of
|
|||
|
|
accounts in the following format:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
machine <em class="replaceable"><code>my-machine</code></em>
|
|||
|
|
login <em class="replaceable"><code>my-username</code></em>
|
|||
|
|
password <em class="replaceable"><code>my-password</code></em>
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
For the exact syntax, see <a class="link" href="https://ec.haxx.se/usingcurl-netrc.html" target="_top">the
|
|||
|
|
<code class="literal">curl</code> documentation.</a></p><div class="note"><h3 class="title">Note</h3><p>This must be an absolute path, and <code class="literal">~</code>
|
|||
|
|
is not resolved. For example, <code class="filename">~/.netrc</code> won't
|
|||
|
|
resolve to your home directory's <code class="filename">.netrc</code>.</p></div></dd><dt><a id="conf-plugin-files"></a><span class="term"><code class="literal">plugin-files</code></span></dt><dd><p>
|
|||
|
|
A list of plugin files to be loaded by Nix. Each of these
|
|||
|
|
files will be dlopened by Nix, allowing them to affect
|
|||
|
|
execution through static initialization. In particular, these
|
|||
|
|
plugins may construct static instances of RegisterPrimOp to
|
|||
|
|
add new primops or constants to the expression language,
|
|||
|
|
RegisterStoreImplementation to add new store implementations,
|
|||
|
|
RegisterCommand to add new subcommands to the
|
|||
|
|
<code class="literal">nix</code> command, and RegisterSetting to add new
|
|||
|
|
nix config settings. See the constructors for those types for
|
|||
|
|
more details.
|
|||
|
|
</p><p>
|
|||
|
|
Since these files are loaded into the same address space as
|
|||
|
|
Nix itself, they must be DSOs compatible with the instance of
|
|||
|
|
Nix running at the time (i.e. compiled against the same
|
|||
|
|
headers, not linked to any incompatible libraries). They
|
|||
|
|
should not be linked to any Nix libs directly, as those will
|
|||
|
|
be available already at load time.
|
|||
|
|
</p><p>
|
|||
|
|
If an entry in the list is a directory, all files in the
|
|||
|
|
directory are loaded as plugins (non-recursively).
|
|||
|
|
</p></dd><dt><a id="conf-pre-build-hook"></a><span class="term"><code class="literal">pre-build-hook</code></span></dt><dd><p>If set, the path to a program that can set extra
|
|||
|
|
derivation-specific settings for this system. This is used for settings
|
|||
|
|
that can't be captured by the derivation model itself and are too variable
|
|||
|
|
between different versions of the same system to be hard-coded into nix.
|
|||
|
|
</p><p>The hook is passed the derivation path and, if sandboxes are enabled,
|
|||
|
|
the sandbox directory. It can then modify the sandbox and send a series of
|
|||
|
|
commands to modify various settings to stdout. The currently recognized
|
|||
|
|
commands are:</p><div class="variablelist"><dl class="variablelist"><dt><a id="extra-sandbox-paths"></a><span class="term"><code class="literal">extra-sandbox-paths</code></span></dt><dd><p>Pass a list of files and directories to be included in the
|
|||
|
|
sandbox for this build. One entry per line, terminated by an empty
|
|||
|
|
line. Entries have the same format as
|
|||
|
|
<code class="literal">sandbox-paths</code>.</p></dd></dl></div></dd><dt><a id="conf-post-build-hook"></a><span class="term"><code class="literal">post-build-hook</code></span></dt><dd><p>Optional. The path to a program to execute after each build.</p><p>This option is only settable in the global
|
|||
|
|
<code class="filename">nix.conf</code>, or on the command line by trusted
|
|||
|
|
users.</p><p>When using the nix-daemon, the daemon executes the hook as
|
|||
|
|
<code class="literal">root</code>. If the nix-daemon is not involved, the
|
|||
|
|
hook runs as the user executing the nix-build.</p><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><p>The hook executes after an evaluation-time build.</p></li><li class="listitem"><p>The hook does not execute on substituted paths.</p></li><li class="listitem"><p>The hook's output always goes to the user's terminal.</p></li><li class="listitem"><p>If the hook fails, the build succeeds but no further builds execute.</p></li><li class="listitem"><p>The hook executes synchronously, and blocks other builds from progressing while it runs.</p></li></ul></div><p>The program executes with no arguments. The program's environment
|
|||
|
|
contains the following environment variables:</p><div class="variablelist"><dl class="variablelist"><dt><span class="term"><code class="envar">DRV_PATH</code></span></dt><dd><p>The derivation for the built paths.</p><p>Example:
|
|||
|
|
<code class="literal">/nix/store/5nihn1a7pa8b25l9zafqaqibznlvvp3f-bash-4.4-p23.drv</code>
|
|||
|
|
</p></dd><dt><span class="term"><code class="envar">OUT_PATHS</code></span></dt><dd><p>Output paths of the built derivation, separated by a space character.</p><p>Example:
|
|||
|
|
<code class="literal">/nix/store/zf5lbh336mnzf1nlswdn11g4n2m8zh3g-bash-4.4-p23-dev
|
|||
|
|
/nix/store/rjxwxwv1fpn9wa2x5ssk5phzwlcv4mna-bash-4.4-p23-doc
|
|||
|
|
/nix/store/6bqvbzjkcp9695dq0dpl5y43nvy37pq1-bash-4.4-p23-info
|
|||
|
|
/nix/store/r7fng3kk3vlpdlh2idnrbn37vh4imlj2-bash-4.4-p23-man
|
|||
|
|
/nix/store/xfghy8ixrhz3kyy6p724iv3cxji088dx-bash-4.4-p23</code>.
|
|||
|
|
</p></dd></dl></div><p>See <a class="xref" href="#chap-post-build-hook" title="Chapter 19. Using the post-build-hook">Chapter 19, <em>Using the <code class="option"><a class="option" href="#conf-post-build-hook">post-build-hook</a></code></em></a> for an example
|
|||
|
|
implementation.</p></dd><dt><a id="conf-repeat"></a><span class="term"><code class="literal">repeat</code></span></dt><dd><p>How many times to repeat builds to check whether
|
|||
|
|
they are deterministic. The default value is 0. If the value is
|
|||
|
|
non-zero, every build is repeated the specified number of
|
|||
|
|
times. If the contents of any of the runs differs from the
|
|||
|
|
previous ones and <a class="xref" href="#conf-enforce-determinism"><code class="literal">enforce-determinism</code></a> is
|
|||
|
|
true, the build is rejected and the resulting store paths are not
|
|||
|
|
registered as “valid” in Nix’s database.</p></dd><dt><a id="conf-require-sigs"></a><span class="term"><code class="literal">require-sigs</code></span></dt><dd><p>If set to <code class="literal">true</code> (the default),
|
|||
|
|
any non-content-addressed path added or copied to the Nix store
|
|||
|
|
(e.g. when substituting from a binary cache) must have a valid
|
|||
|
|
signature, that is, be signed using one of the keys listed in
|
|||
|
|
<code class="option">trusted-public-keys</code> or
|
|||
|
|
<code class="option">secret-key-files</code>. Set to <code class="literal">false</code>
|
|||
|
|
to disable signature checking.</p></dd><dt><a id="conf-restrict-eval"></a><span class="term"><code class="literal">restrict-eval</code></span></dt><dd><p>If set to <code class="literal">true</code>, the Nix evaluator will
|
|||
|
|
not allow access to any files outside of the Nix search path (as
|
|||
|
|
set via the <code class="envar">NIX_PATH</code> environment variable or the
|
|||
|
|
<code class="option">-I</code> option), or to URIs outside of
|
|||
|
|
<code class="option">allowed-uri</code>. The default is
|
|||
|
|
<code class="literal">false</code>.</p></dd><dt><a id="conf-run-diff-hook"></a><span class="term"><code class="literal">run-diff-hook</code></span></dt><dd><p>
|
|||
|
|
If true, enable the execution of <a class="xref" href="#conf-diff-hook"><code class="literal">diff-hook</code></a>.
|
|||
|
|
</p><p>
|
|||
|
|
When using the Nix daemon, <code class="literal">run-diff-hook</code> must
|
|||
|
|
be set in the <code class="filename">nix.conf</code> configuration file,
|
|||
|
|
and cannot be passed at the command line.
|
|||
|
|
</p></dd><dt><a id="conf-sandbox"></a><span class="term"><code class="literal">sandbox</code></span></dt><dd><p>If set to <code class="literal">true</code>, builds will be
|
|||
|
|
performed in a <span class="emphasis"><em>sandboxed environment</em></span>, i.e.,
|
|||
|
|
they’re isolated from the normal file system hierarchy and will
|
|||
|
|
only see their dependencies in the Nix store, the temporary build
|
|||
|
|
directory, private versions of <code class="filename">/proc</code>,
|
|||
|
|
<code class="filename">/dev</code>, <code class="filename">/dev/shm</code> and
|
|||
|
|
<code class="filename">/dev/pts</code> (on Linux), and the paths configured with the
|
|||
|
|
<a class="link" href="#conf-sandbox-paths"><code class="literal">sandbox-paths</code>
|
|||
|
|
option</a>. This is useful to prevent undeclared dependencies
|
|||
|
|
on files in directories such as <code class="filename">/usr/bin</code>. In
|
|||
|
|
addition, on Linux, builds run in private PID, mount, network, IPC
|
|||
|
|
and UTS namespaces to isolate them from other processes in the
|
|||
|
|
system (except that fixed-output derivations do not run in private
|
|||
|
|
network namespace to ensure they can access the network).</p><p>Currently, sandboxing only work on Linux and macOS. The use
|
|||
|
|
of a sandbox requires that Nix is run as root (so you should use
|
|||
|
|
the <a class="link" href="#conf-build-users-group">“build users”
|
|||
|
|
feature</a> to perform the actual builds under different users
|
|||
|
|
than root).</p><p>If this option is set to <code class="literal">relaxed</code>, then
|
|||
|
|
fixed-output derivations and derivations that have the
|
|||
|
|
<code class="varname">__noChroot</code> attribute set to
|
|||
|
|
<code class="literal">true</code> do not run in sandboxes.</p><p>The default is <code class="literal">true</code> on Linux and
|
|||
|
|
<code class="literal">false</code> on all other platforms.</p></dd><dt><a id="conf-sandbox-dev-shm-size"></a><span class="term"><code class="literal">sandbox-dev-shm-size</code></span></dt><dd><p>This option determines the maximum size of the
|
|||
|
|
<code class="literal">tmpfs</code> filesystem mounted on
|
|||
|
|
<code class="filename">/dev/shm</code> in Linux sandboxes. For the format,
|
|||
|
|
see the description of the <code class="option">size</code> option of
|
|||
|
|
<code class="literal">tmpfs</code> in
|
|||
|
|
<span class="citerefentry"><span class="refentrytitle">mount</span>(8)</span>. The
|
|||
|
|
default is <code class="literal">50%</code>.</p></dd><dt><a id="conf-sandbox-paths"></a><span class="term"><code class="literal">sandbox-paths</code></span></dt><dd><p>A list of paths bind-mounted into Nix sandbox
|
|||
|
|
environments. You can use the syntax
|
|||
|
|
<code class="literal"><em class="replaceable"><code>target</code></em>=<em class="replaceable"><code>source</code></em></code>
|
|||
|
|
to mount a path in a different location in the sandbox; for
|
|||
|
|
instance, <code class="literal">/bin=/nix-bin</code> will mount the path
|
|||
|
|
<code class="literal">/nix-bin</code> as <code class="literal">/bin</code> inside the
|
|||
|
|
sandbox. If <em class="replaceable"><code>source</code></em> is followed by
|
|||
|
|
<code class="literal">?</code>, then it is not an error if
|
|||
|
|
<em class="replaceable"><code>source</code></em> does not exist; for example,
|
|||
|
|
<code class="literal">/dev/nvidiactl?</code> specifies that
|
|||
|
|
<code class="filename">/dev/nvidiactl</code> will only be mounted in the
|
|||
|
|
sandbox if it exists in the host filesystem.</p><p>Depending on how Nix was built, the default value for this option
|
|||
|
|
may be empty or provide <code class="filename">/bin/sh</code> as a
|
|||
|
|
bind-mount of <span class="command"><strong>bash</strong></span>.</p></dd><dt><a id="conf-secret-key-files"></a><span class="term"><code class="literal">secret-key-files</code></span></dt><dd><p>A whitespace-separated list of files containing
|
|||
|
|
secret (private) keys. These are used to sign locally-built
|
|||
|
|
paths. They can be generated using <span class="command"><strong>nix-store
|
|||
|
|
--generate-binary-cache-key</strong></span>. The corresponding public
|
|||
|
|
key can be distributed to other users, who can add it to
|
|||
|
|
<code class="option">trusted-public-keys</code> in their
|
|||
|
|
<code class="filename">nix.conf</code>.</p></dd><dt><a id="conf-show-trace"></a><span class="term"><code class="literal">show-trace</code></span></dt><dd><p>Causes Nix to print out a stack trace in case of Nix
|
|||
|
|
expression evaluation errors.</p></dd><dt><a id="conf-substitute"></a><span class="term"><code class="literal">substitute</code></span></dt><dd><p>If set to <code class="literal">true</code> (default), Nix
|
|||
|
|
will use binary substitutes if available. This option can be
|
|||
|
|
disabled to force building from source.</p></dd><dt><a id="conf-stalled-download-timeout"></a><span class="term"><code class="literal">stalled-download-timeout</code></span></dt><dd><p>The timeout (in seconds) for receiving data from servers
|
|||
|
|
during download. Nix cancels idle downloads after this timeout's
|
|||
|
|
duration.</p></dd><dt><a id="conf-substituters"></a><span class="term"><code class="literal">substituters</code></span></dt><dd><p>A list of URLs of substituters, separated by
|
|||
|
|
whitespace. The default is
|
|||
|
|
<code class="literal">https://cache.nixos.org</code>.</p></dd><dt><a id="conf-system"></a><span class="term"><code class="literal">system</code></span></dt><dd><p>This option specifies the canonical Nix system
|
|||
|
|
name of the current installation, such as
|
|||
|
|
<code class="literal">i686-linux</code> or
|
|||
|
|
<code class="literal">x86_64-darwin</code>. Nix can only build derivations
|
|||
|
|
whose <code class="literal">system</code> attribute equals the value
|
|||
|
|
specified here. In general, it never makes sense to modify this
|
|||
|
|
value from its default, since you can use it to ‘lie’ about the
|
|||
|
|
platform you are building on (e.g., perform a Mac OS build on a
|
|||
|
|
Linux machine; the result would obviously be wrong). It only
|
|||
|
|
makes sense if the Nix binaries can run on multiple platforms,
|
|||
|
|
e.g., ‘universal binaries’ that run on <code class="literal">x86_64-linux</code> and
|
|||
|
|
<code class="literal">i686-linux</code>.</p><p>It defaults to the canonical Nix system name detected by
|
|||
|
|
<code class="filename">configure</code> at build time.</p></dd><dt><a id="conf-system-features"></a><span class="term"><code class="literal">system-features</code></span></dt><dd><p>A set of system “features” supported by this
|
|||
|
|
machine, e.g. <code class="literal">kvm</code>. Derivations can express a
|
|||
|
|
dependency on such features through the derivation attribute
|
|||
|
|
<code class="varname">requiredSystemFeatures</code>. For example, the
|
|||
|
|
attribute
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
requiredSystemFeatures = [ "kvm" ];
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
ensures that the derivation can only be built on a machine with
|
|||
|
|
the <code class="literal">kvm</code> feature.</p><p>This setting by default includes <code class="literal">kvm</code> if
|
|||
|
|
<code class="filename">/dev/kvm</code> is accessible, and the
|
|||
|
|
pseudo-features <code class="literal">nixos-test</code>,
|
|||
|
|
<code class="literal">benchmark</code> and <code class="literal">big-parallel</code>
|
|||
|
|
that are used in Nixpkgs to route builds to specific
|
|||
|
|
machines.</p></dd><dt><a id="conf-tarball-ttl"></a><span class="term"><code class="literal">tarball-ttl</code></span></dt><dd><p>Default: <code class="literal">3600</code> seconds.</p><p>The number of seconds a downloaded tarball is considered
|
|||
|
|
fresh. If the cached tarball is stale, Nix will check whether
|
|||
|
|
it is still up to date using the ETag header. Nix will download
|
|||
|
|
a new version if the ETag header is unsupported, or the
|
|||
|
|
cached ETag doesn't match.
|
|||
|
|
</p><p>Setting the TTL to <code class="literal">0</code> forces Nix to always
|
|||
|
|
check if the tarball is up to date.</p><p>Nix caches tarballs in
|
|||
|
|
<code class="filename">$XDG_CACHE_HOME/nix/tarballs</code>.</p><p>Files fetched via <code class="envar">NIX_PATH</code>,
|
|||
|
|
<code class="function">fetchGit</code>, <code class="function">fetchMercurial</code>,
|
|||
|
|
<code class="function">fetchTarball</code>, and <code class="function">fetchurl</code>
|
|||
|
|
respect this TTL.
|
|||
|
|
</p></dd><dt><a id="conf-timeout"></a><span class="term"><code class="literal">timeout</code></span></dt><dd><p>This option defines the maximum number of seconds that a
|
|||
|
|
builder can run. This is useful (for instance in an automated
|
|||
|
|
build system) to catch builds that are stuck in an infinite loop
|
|||
|
|
but keep writing to their standard output or standard error. It
|
|||
|
|
can be overridden using the <code class="option"><a class="option" href="#opt-timeout">--timeout</a></code> command line
|
|||
|
|
switch.</p><p>The value <code class="literal">0</code> means that there is no
|
|||
|
|
timeout. This is also the default.</p></dd><dt><a id="conf-trace-function-calls"></a><span class="term"><code class="literal">trace-function-calls</code></span></dt><dd><p>Default: <code class="literal">false</code>.</p><p>If set to <code class="literal">true</code>, the Nix evaluator will
|
|||
|
|
trace every function call. Nix will print a log message at the
|
|||
|
|
"vomit" level for every function entrance and function exit.</p><div class="informalexample"><pre class="screen">
|
|||
|
|
function-trace entered undefined position at 1565795816999559622
|
|||
|
|
function-trace exited undefined position at 1565795816999581277
|
|||
|
|
function-trace entered /nix/store/.../example.nix:226:41 at 1565795253249935150
|
|||
|
|
function-trace exited /nix/store/.../example.nix:226:41 at 1565795253249941684
|
|||
|
|
</pre></div><p>The <code class="literal">undefined position</code> means the function
|
|||
|
|
call is a builtin.</p><p>Use the <code class="literal">contrib/stack-collapse.py</code> script
|
|||
|
|
distributed with the Nix source code to convert the trace logs
|
|||
|
|
in to a format suitable for <span class="command"><strong>flamegraph.pl</strong></span>.</p></dd><dt><a id="conf-trusted-public-keys"></a><span class="term"><code class="literal">trusted-public-keys</code></span></dt><dd><p>A whitespace-separated list of public keys. When
|
|||
|
|
paths are copied from another Nix store (such as a binary cache),
|
|||
|
|
they must be signed with one of these keys. For example:
|
|||
|
|
<code class="literal">cache.nixos.org-1:6NCHdD59X431o0gWypbMrAURkbJ16ZPMQFGspcDShjY=
|
|||
|
|
hydra.nixos.org-1:CNHJZBh9K4tP3EKF6FkkgeVYsS3ohTl+oS0Qa8bezVs=</code>.</p></dd><dt><a id="conf-trusted-substituters"></a><span class="term"><code class="literal">trusted-substituters</code></span></dt><dd><p>A list of URLs of substituters, separated by
|
|||
|
|
whitespace. These are not used by default, but can be enabled by
|
|||
|
|
users of the Nix daemon by specifying <code class="literal">--option
|
|||
|
|
substituters <em class="replaceable"><code>urls</code></em></code> on the
|
|||
|
|
command line. Unprivileged users are only allowed to pass a
|
|||
|
|
subset of the URLs listed in <code class="literal">substituters</code> and
|
|||
|
|
<code class="literal">trusted-substituters</code>.</p></dd><dt><a id="conf-trusted-users"></a><span class="term"><code class="literal">trusted-users</code></span></dt><dd><p>A list of names of users (separated by whitespace) that
|
|||
|
|
have additional rights when connecting to the Nix daemon, such
|
|||
|
|
as the ability to specify additional binary caches, or to import
|
|||
|
|
unsigned NARs. You can also specify groups by prefixing them
|
|||
|
|
with <code class="literal">@</code>; for instance,
|
|||
|
|
<code class="literal">@wheel</code> means all users in the
|
|||
|
|
<code class="literal">wheel</code> group. The default is
|
|||
|
|
<code class="literal">root</code>.</p><div class="warning"><h3 class="title">Warning</h3><p>Adding a user to <code class="option">trusted-users</code>
|
|||
|
|
is essentially equivalent to giving that user root access to the
|
|||
|
|
system. For example, the user can set
|
|||
|
|
<code class="option">sandbox-paths</code> and thereby obtain read access to
|
|||
|
|
directories that are otherwise inacessible to
|
|||
|
|
them.</p></div></dd></dl></div><p>
|
|||
|
|
</p><div class="refsection"><a id="idm139733298856336"></a><h3>Deprecated Settings</h3><p>
|
|||
|
|
|
|||
|
|
</p><div class="variablelist"><dl class="variablelist"><dt><a id="conf-binary-caches"></a><span class="term"><code class="literal">binary-caches</code></span></dt><dd><p><span class="emphasis"><em>Deprecated:</em></span>
|
|||
|
|
<code class="literal">binary-caches</code> is now an alias to
|
|||
|
|
<a class="xref" href="#conf-substituters"><code class="literal">substituters</code></a>.</p></dd><dt><a id="conf-binary-cache-public-keys"></a><span class="term"><code class="literal">binary-cache-public-keys</code></span></dt><dd><p><span class="emphasis"><em>Deprecated:</em></span>
|
|||
|
|
<code class="literal">binary-cache-public-keys</code> is now an alias to
|
|||
|
|
<a class="xref" href="#conf-trusted-public-keys"><code class="literal">trusted-public-keys</code></a>.</p></dd><dt><a id="conf-build-compress-log"></a><span class="term"><code class="literal">build-compress-log</code></span></dt><dd><p><span class="emphasis"><em>Deprecated:</em></span>
|
|||
|
|
<code class="literal">build-compress-log</code> is now an alias to
|
|||
|
|
<a class="xref" href="#conf-compress-build-log"><code class="literal">compress-build-log</code></a>.</p></dd><dt><a id="conf-build-cores"></a><span class="term"><code class="literal">build-cores</code></span></dt><dd><p><span class="emphasis"><em>Deprecated:</em></span>
|
|||
|
|
<code class="literal">build-cores</code> is now an alias to
|
|||
|
|
<a class="xref" href="#conf-cores"><code class="literal">cores</code></a>.</p></dd><dt><a id="conf-build-extra-chroot-dirs"></a><span class="term"><code class="literal">build-extra-chroot-dirs</code></span></dt><dd><p><span class="emphasis"><em>Deprecated:</em></span>
|
|||
|
|
<code class="literal">build-extra-chroot-dirs</code> is now an alias to
|
|||
|
|
<a class="xref" href="#conf-extra-sandbox-paths"><code class="literal">extra-sandbox-paths</code></a>.</p></dd><dt><a id="conf-build-extra-sandbox-paths"></a><span class="term"><code class="literal">build-extra-sandbox-paths</code></span></dt><dd><p><span class="emphasis"><em>Deprecated:</em></span>
|
|||
|
|
<code class="literal">build-extra-sandbox-paths</code> is now an alias to
|
|||
|
|
<a class="xref" href="#conf-extra-sandbox-paths"><code class="literal">extra-sandbox-paths</code></a>.</p></dd><dt><a id="conf-build-fallback"></a><span class="term"><code class="literal">build-fallback</code></span></dt><dd><p><span class="emphasis"><em>Deprecated:</em></span>
|
|||
|
|
<code class="literal">build-fallback</code> is now an alias to
|
|||
|
|
<a class="xref" href="#conf-fallback"><code class="literal">fallback</code></a>.</p></dd><dt><a id="conf-build-max-jobs"></a><span class="term"><code class="literal">build-max-jobs</code></span></dt><dd><p><span class="emphasis"><em>Deprecated:</em></span>
|
|||
|
|
<code class="literal">build-max-jobs</code> is now an alias to
|
|||
|
|
<a class="xref" href="#conf-max-jobs"><code class="literal">max-jobs</code></a>.</p></dd><dt><a id="conf-build-max-log-size"></a><span class="term"><code class="literal">build-max-log-size</code></span></dt><dd><p><span class="emphasis"><em>Deprecated:</em></span>
|
|||
|
|
<code class="literal">build-max-log-size</code> is now an alias to
|
|||
|
|
<a class="xref" href="#conf-max-build-log-size"><code class="literal">max-build-log-size</code></a>.</p></dd><dt><a id="conf-build-max-silent-time"></a><span class="term"><code class="literal">build-max-silent-time</code></span></dt><dd><p><span class="emphasis"><em>Deprecated:</em></span>
|
|||
|
|
<code class="literal">build-max-silent-time</code> is now an alias to
|
|||
|
|
<a class="xref" href="#conf-max-silent-time"><code class="literal">max-silent-time</code></a>.</p></dd><dt><a id="conf-build-repeat"></a><span class="term"><code class="literal">build-repeat</code></span></dt><dd><p><span class="emphasis"><em>Deprecated:</em></span>
|
|||
|
|
<code class="literal">build-repeat</code> is now an alias to
|
|||
|
|
<a class="xref" href="#conf-repeat"><code class="literal">repeat</code></a>.</p></dd><dt><a id="conf-build-timeout"></a><span class="term"><code class="literal">build-timeout</code></span></dt><dd><p><span class="emphasis"><em>Deprecated:</em></span>
|
|||
|
|
<code class="literal">build-timeout</code> is now an alias to
|
|||
|
|
<a class="xref" href="#conf-timeout"><code class="literal">timeout</code></a>.</p></dd><dt><a id="conf-build-use-chroot"></a><span class="term"><code class="literal">build-use-chroot</code></span></dt><dd><p><span class="emphasis"><em>Deprecated:</em></span>
|
|||
|
|
<code class="literal">build-use-chroot</code> is now an alias to
|
|||
|
|
<a class="xref" href="#conf-sandbox"><code class="literal">sandbox</code></a>.</p></dd><dt><a id="conf-build-use-sandbox"></a><span class="term"><code class="literal">build-use-sandbox</code></span></dt><dd><p><span class="emphasis"><em>Deprecated:</em></span>
|
|||
|
|
<code class="literal">build-use-sandbox</code> is now an alias to
|
|||
|
|
<a class="xref" href="#conf-sandbox"><code class="literal">sandbox</code></a>.</p></dd><dt><a id="conf-build-use-substitutes"></a><span class="term"><code class="literal">build-use-substitutes</code></span></dt><dd><p><span class="emphasis"><em>Deprecated:</em></span>
|
|||
|
|
<code class="literal">build-use-substitutes</code> is now an alias to
|
|||
|
|
<a class="xref" href="#conf-substitute"><code class="literal">substitute</code></a>.</p></dd><dt><a id="conf-gc-keep-derivations"></a><span class="term"><code class="literal">gc-keep-derivations</code></span></dt><dd><p><span class="emphasis"><em>Deprecated:</em></span>
|
|||
|
|
<code class="literal">gc-keep-derivations</code> is now an alias to
|
|||
|
|
<a class="xref" href="#conf-keep-derivations"><code class="literal">keep-derivations</code></a>.</p></dd><dt><a id="conf-gc-keep-outputs"></a><span class="term"><code class="literal">gc-keep-outputs</code></span></dt><dd><p><span class="emphasis"><em>Deprecated:</em></span>
|
|||
|
|
<code class="literal">gc-keep-outputs</code> is now an alias to
|
|||
|
|
<a class="xref" href="#conf-keep-outputs"><code class="literal">keep-outputs</code></a>.</p></dd><dt><a id="conf-env-keep-derivations"></a><span class="term"><code class="literal">env-keep-derivations</code></span></dt><dd><p><span class="emphasis"><em>Deprecated:</em></span>
|
|||
|
|
<code class="literal">env-keep-derivations</code> is now an alias to
|
|||
|
|
<a class="xref" href="#conf-keep-env-derivations"><code class="literal">keep-env-derivations</code></a>.</p></dd><dt><a id="conf-extra-binary-caches"></a><span class="term"><code class="literal">extra-binary-caches</code></span></dt><dd><p><span class="emphasis"><em>Deprecated:</em></span>
|
|||
|
|
<code class="literal">extra-binary-caches</code> is now an alias to
|
|||
|
|
<a class="xref" href="#conf-extra-substituters"><code class="literal">extra-substituters</code></a>.</p></dd><dt><a id="conf-trusted-binary-caches"></a><span class="term"><code class="literal">trusted-binary-caches</code></span></dt><dd><p><span class="emphasis"><em>Deprecated:</em></span>
|
|||
|
|
<code class="literal">trusted-binary-caches</code> is now an alias to
|
|||
|
|
<a class="xref" href="#conf-trusted-substituters"><code class="literal">trusted-substituters</code></a>.</p></dd></dl></div><p>
|
|||
|
|
</p></div></div></div></div></div><div class="appendix"><div class="titlepage"><div><div><h1 class="title"><a id="part-glossary"></a>Appendix A. Glossary</h1></div></div></div><div class="glosslist"><dl><dt><a id="gloss-derivation"></a><span class="glossterm">derivation</span></dt><dd class="glossdef"><p>A description of a build action. The result of a
|
|||
|
|
derivation is a store object. Derivations are typically specified
|
|||
|
|
in Nix expressions using the <a class="link" href="#ssec-derivation" title="15.4. Derivations"><code class="function">derivation</code>
|
|||
|
|
primitive</a>. These are translated into low-level
|
|||
|
|
<span class="emphasis"><em>store derivations</em></span> (implicitly by
|
|||
|
|
<span class="command"><strong>nix-env</strong></span> and <span class="command"><strong>nix-build</strong></span>, or
|
|||
|
|
explicitly by <span class="command"><strong>nix-instantiate</strong></span>).</p></dd><dt><span class="glossterm">store</span></dt><dd class="glossdef"><p>The location in the file system where store objects
|
|||
|
|
live. Typically <code class="filename">/nix/store</code>.</p></dd><dt><span class="glossterm">store path</span></dt><dd class="glossdef"><p>The location in the file system of a store object,
|
|||
|
|
i.e., an immediate child of the Nix store
|
|||
|
|
directory.</p></dd><dt><span class="glossterm">store object</span></dt><dd class="glossdef"><p>A file that is an immediate child of the Nix store
|
|||
|
|
directory. These can be regular files, but also entire directory
|
|||
|
|
trees. Store objects can be sources (objects copied from outside of
|
|||
|
|
the store), derivation outputs (objects produced by running a build
|
|||
|
|
action), or derivations (files describing a build
|
|||
|
|
action).</p></dd><dt><a id="gloss-substitute"></a><span class="glossterm">substitute</span></dt><dd class="glossdef"><p>A substitute is a command invocation stored in the
|
|||
|
|
Nix database that describes how to build a store object, bypassing
|
|||
|
|
the normal build mechanism (i.e., derivations). Typically, the
|
|||
|
|
substitute builds the store object by downloading a pre-built
|
|||
|
|
version of the store object from some server.</p></dd><dt><span class="glossterm">purity</span></dt><dd class="glossdef"><p>The assumption that equal Nix derivations when run
|
|||
|
|
always produce the same output. This cannot be guaranteed in
|
|||
|
|
general (e.g., a builder can rely on external inputs such as the
|
|||
|
|
network or the system time) but the Nix model assumes
|
|||
|
|
it.</p></dd><dt><span class="glossterm">Nix expression</span></dt><dd class="glossdef"><p>A high-level description of software packages and
|
|||
|
|
compositions thereof. Deploying software using Nix entails writing
|
|||
|
|
Nix expressions for your packages. Nix expressions are translated
|
|||
|
|
to derivations that are stored in the Nix store. These derivations
|
|||
|
|
can then be built.</p></dd><dt><a id="gloss-reference"></a><span class="glossterm">reference</span></dt><dd class="glossdef"><p>A store path <code class="varname">P</code> is said to have a
|
|||
|
|
reference to a store path <code class="varname">Q</code> if the store object
|
|||
|
|
at <code class="varname">P</code> contains the path <code class="varname">Q</code>
|
|||
|
|
somewhere. The <span class="emphasis"><em>references</em></span> of a store path are
|
|||
|
|
the set of store paths to which it has a reference.
|
|||
|
|
</p><p>A derivation can reference other derivations and sources
|
|||
|
|
(but not output paths), whereas an output path only references other
|
|||
|
|
output paths.
|
|||
|
|
</p></dd><dt><a id="gloss-reachable"></a><span class="glossterm">reachable</span></dt><dd class="glossdef"><p>A store path <code class="varname">Q</code> is reachable from
|
|||
|
|
another store path <code class="varname">P</code> if <code class="varname">Q</code> is in the
|
|||
|
|
<a class="link" href="#gloss-closure" title="closure">closure</a> of the
|
|||
|
|
<a class="link" href="#gloss-reference" title="reference">references</a> relation.
|
|||
|
|
</p></dd><dt><a id="gloss-closure"></a><span class="glossterm">closure</span></dt><dd class="glossdef"><p>The closure of a store path is the set of store
|
|||
|
|
paths that are directly or indirectly “reachable” from that store
|
|||
|
|
path; that is, it’s the closure of the path under the <a class="link" href="#gloss-reference" title="reference">references</a> relation. For a package, the
|
|||
|
|
closure of its derivation is equivalent to the build-time
|
|||
|
|
dependencies, while the closure of its output path is equivalent to its
|
|||
|
|
runtime dependencies. For correct deployment it is necessary to deploy whole
|
|||
|
|
closures, since otherwise at runtime files could be missing. The command
|
|||
|
|
<span class="command"><strong>nix-store -qR</strong></span> prints out closures of store paths.
|
|||
|
|
</p><p>As an example, if the store object at path <code class="varname">P</code> contains
|
|||
|
|
a reference to path <code class="varname">Q</code>, then <code class="varname">Q</code> is
|
|||
|
|
in the closure of <code class="varname">P</code>. Further, if <code class="varname">Q</code>
|
|||
|
|
references <code class="varname">R</code> then <code class="varname">R</code> is also in
|
|||
|
|
the closure of <code class="varname">P</code>.
|
|||
|
|
</p></dd><dt><a id="gloss-output-path"></a><span class="glossterm">output path</span></dt><dd class="glossdef"><p>A store path produced by a derivation.</p></dd><dt><a id="gloss-deriver"></a><span class="glossterm">deriver</span></dt><dd class="glossdef"><p>The deriver of an <a class="link" href="#gloss-output-path" title="output path">output path</a> is the store
|
|||
|
|
derivation that built it.</p></dd><dt><a id="gloss-validity"></a><span class="glossterm">validity</span></dt><dd class="glossdef"><p>A store path is considered
|
|||
|
|
<span class="emphasis"><em>valid</em></span> if it exists in the file system, is
|
|||
|
|
listed in the Nix database as being valid, and if all paths in its
|
|||
|
|
closure are also valid.</p></dd><dt><a id="gloss-user-env"></a><span class="glossterm">user environment</span></dt><dd class="glossdef"><p>An automatically generated store object that
|
|||
|
|
consists of a set of symlinks to “active” applications, i.e., other
|
|||
|
|
store paths. These are generated automatically by <a class="link" href="#sec-nix-env" title="nix-env"><span class="command"><strong>nix-env</strong></span></a>. See <a class="xref" href="#sec-profiles" title="Chapter 10. Profiles">Chapter 10, <em>Profiles</em></a>.</p></dd><dt><a id="gloss-profile"></a><span class="glossterm">profile</span></dt><dd class="glossdef"><p>A symlink to the current <a class="link" href="#gloss-user-env" title="user environment">user environment</a> of a user, e.g.,
|
|||
|
|
<code class="filename">/nix/var/nix/profiles/default</code>.</p></dd><dt><a id="gloss-nar"></a><span class="glossterm">NAR</span></dt><dd class="glossdef"><p>A <span class="emphasis"><em>N</em></span>ix
|
|||
|
|
<span class="emphasis"><em>AR</em></span>chive. This is a serialisation of a path in
|
|||
|
|
the Nix store. It can contain regular files, directories and
|
|||
|
|
symbolic links. NARs are generated and unpacked using
|
|||
|
|
<span class="command"><strong>nix-store --dump</strong></span> and <span class="command"><strong>nix-store
|
|||
|
|
--restore</strong></span>.</p></dd></dl></div></div><div class="appendix"><div class="titlepage"><div><div><h1 class="title"><a id="chap-hacking"></a>Appendix B. Hacking</h1></div></div></div><p>This section provides some notes on how to hack on Nix. To get
|
|||
|
|
the latest version of Nix from GitHub:
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ git clone https://github.com/NixOS/nix.git
|
|||
|
|
$ cd nix
|
|||
|
|
</pre><p>
|
|||
|
|
</p><p>To build Nix for the current operating system/architecture use
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-build
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
or if you have a flakes-enabled nix:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix build
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
This will build <code class="literal">defaultPackage</code> attribute defined in the <code class="literal">flake.nix</code> file.
|
|||
|
|
|
|||
|
|
To build for other platforms add one of the following suffixes to it: aarch64-linux,
|
|||
|
|
i686-linux, x86_64-darwin, x86_64-linux.
|
|||
|
|
|
|||
|
|
i.e.
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
nix-build -A defaultPackage.x86_64-linux
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
</p><p>To build all dependencies and start a shell in which all
|
|||
|
|
environment variables are set up so that those dependencies can be
|
|||
|
|
found:
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-shell
|
|||
|
|
</pre><p>
|
|||
|
|
To build Nix itself in this shell:
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
[nix-shell]$ ./bootstrap.sh
|
|||
|
|
[nix-shell]$ ./configure $configureFlags
|
|||
|
|
[nix-shell]$ make -j $NIX_BUILD_CORES
|
|||
|
|
</pre><p>
|
|||
|
|
To install it in <code class="literal">$(pwd)/inst</code> and test it:
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
[nix-shell]$ make install
|
|||
|
|
[nix-shell]$ make installcheck
|
|||
|
|
[nix-shell]$ ./inst/bin/nix --version
|
|||
|
|
nix (Nix) 2.4
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
If you have a flakes-enabled nix you can replace:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-shell
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
by:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix develop
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
</p></div><div class="appendix"><div class="titlepage"><div><div><h1 class="title"><a id="sec-relnotes"></a>Appendix C. Nix Release Notes</h1></div></div></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a id="ssec-relnotes-2.3"></a>C.1. Release 2.3 (2019-09-04)</h2></div></div></div><p>This is primarily a bug fix release. However, it makes some
|
|||
|
|
incompatible changes:</p><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><p>Nix now uses BSD file locks instead of POSIX file
|
|||
|
|
locks. Because of this, you should not use Nix 2.3 and previous
|
|||
|
|
releases at the same time on a Nix store.</p></li></ul></div><p>It also has the following changes:</p><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><p><code class="function">builtins.fetchGit</code>'s <code class="varname">ref</code>
|
|||
|
|
argument now allows specifying an absolute remote ref.
|
|||
|
|
Nix will automatically prefix <code class="varname">ref</code> with
|
|||
|
|
<code class="literal">refs/heads</code> only if <code class="varname">ref</code> doesn't
|
|||
|
|
already begin with <code class="literal">refs/</code>.
|
|||
|
|
</p></li><li class="listitem"><p>The installer now enables sandboxing by default on Linux when the
|
|||
|
|
system has the necessary kernel support.
|
|||
|
|
</p></li><li class="listitem"><p>The <code class="literal">max-jobs</code> setting now defaults to 1.</p></li><li class="listitem"><p>New builtin functions:
|
|||
|
|
<code class="literal">builtins.isPath</code>,
|
|||
|
|
<code class="literal">builtins.hashFile</code>.
|
|||
|
|
</p></li><li class="listitem"><p>The <span class="command"><strong>nix</strong></span> command has a new
|
|||
|
|
<code class="option">--print-build-logs</code> (<code class="option">-L</code>) flag to
|
|||
|
|
print build log output to stderr, rather than showing the last log
|
|||
|
|
line in the progress bar. To distinguish between concurrent
|
|||
|
|
builds, log lines are prefixed by the name of the package.
|
|||
|
|
</p></li><li class="listitem"><p>Builds are now executed in a pseudo-terminal, and the
|
|||
|
|
<code class="envar">TERM</code> environment variable is set to
|
|||
|
|
<code class="literal">xterm-256color</code>. This allows many programs
|
|||
|
|
(e.g. <span class="command"><strong>gcc</strong></span>, <span class="command"><strong>clang</strong></span>,
|
|||
|
|
<span class="command"><strong>cmake</strong></span>) to print colorized log output.</p></li><li class="listitem"><p>Add <code class="option">--no-net</code> convenience flag. This flag
|
|||
|
|
disables substituters; sets the <code class="literal">tarball-ttl</code>
|
|||
|
|
setting to infinity (ensuring that any previously downloaded files
|
|||
|
|
are considered current); and disables retrying downloads and sets
|
|||
|
|
the connection timeout to the minimum. This flag is enabled
|
|||
|
|
automatically if there are no configured non-loopback network
|
|||
|
|
interfaces.</p></li><li class="listitem"><p>Add a <code class="literal">post-build-hook</code> setting to run a
|
|||
|
|
program after a build has succeeded.</p></li><li class="listitem"><p>Add a <code class="literal">trace-function-calls</code> setting to log
|
|||
|
|
the duration of Nix function calls to stderr.</p></li></ul></div></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a id="ssec-relnotes-2.2"></a>C.2. Release 2.2 (2019-01-11)</h2></div></div></div><p>This is primarily a bug fix release. It also has the following
|
|||
|
|
changes:</p><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><p>In derivations that use structured attributes (i.e. that
|
|||
|
|
specify set the <code class="varname">__structuredAttrs</code> attribute to
|
|||
|
|
<code class="literal">true</code> to cause all attributes to be passed to
|
|||
|
|
the builder in JSON format), you can now specify closure checks
|
|||
|
|
per output, e.g.:
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
outputChecks."out" = {
|
|||
|
|
# The closure of 'out' must not be larger than 256 MiB.
|
|||
|
|
maxClosureSize = 256 * 1024 * 1024;
|
|||
|
|
|
|||
|
|
# It must not refer to C compiler or to the 'dev' output.
|
|||
|
|
disallowedRequisites = [ stdenv.cc "dev" ];
|
|||
|
|
};
|
|||
|
|
|
|||
|
|
outputChecks."dev" = {
|
|||
|
|
# The 'dev' output must not be larger than 128 KiB.
|
|||
|
|
maxSize = 128 * 1024;
|
|||
|
|
};
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
</p></li><li class="listitem"><p>The derivation attribute
|
|||
|
|
<code class="varname">requiredSystemFeatures</code> is now enforced for
|
|||
|
|
local builds, and not just to route builds to remote builders.
|
|||
|
|
The supported features of a machine can be specified through the
|
|||
|
|
configuration setting <code class="varname">system-features</code>.</p><p>By default, <code class="varname">system-features</code> includes
|
|||
|
|
<code class="literal">kvm</code> if <code class="filename">/dev/kvm</code>
|
|||
|
|
exists. For compatibility, it also includes the pseudo-features
|
|||
|
|
<code class="literal">nixos-test</code>, <code class="literal">benchmark</code> and
|
|||
|
|
<code class="literal">big-parallel</code> which are used by Nixpkgs to route
|
|||
|
|
builds to particular Hydra build machines.</p></li><li class="listitem"><p>Sandbox builds are now enabled by default on Linux.</p></li><li class="listitem"><p>The new command <span class="command"><strong>nix doctor</strong></span> shows
|
|||
|
|
potential issues with your Nix installation.</p></li><li class="listitem"><p>The <code class="literal">fetchGit</code> builtin function now uses a
|
|||
|
|
caching scheme that puts different remote repositories in distinct
|
|||
|
|
local repositories, rather than a single shared repository. This
|
|||
|
|
may require more disk space but is faster.</p></li><li class="listitem"><p>The <code class="literal">dirOf</code> builtin function now works on
|
|||
|
|
relative paths.</p></li><li class="listitem"><p>Nix now supports <a class="link" href="https://www.w3.org/TR/SRI/" target="_top">SRI hashes</a>,
|
|||
|
|
allowing the hash algorithm and hash to be specified in a single
|
|||
|
|
string. For example, you can write:
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
import <nix/fetchurl.nix> {
|
|||
|
|
url = https://nixos.org/releases/nix/nix-2.1.3/nix-2.1.3.tar.xz;
|
|||
|
|
hash = "sha256-XSLa0FjVyADWWhFfkZ2iKTjFDda6mMXjoYMXLRSYQKQ=";
|
|||
|
|
};
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
instead of
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
import <nix/fetchurl.nix> {
|
|||
|
|
url = https://nixos.org/releases/nix/nix-2.1.3/nix-2.1.3.tar.xz;
|
|||
|
|
sha256 = "5d22dad058d5c800d65a115f919da22938c50dd6ba98c5e3a183172d149840a4";
|
|||
|
|
};
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
</p><p>In fixed-output derivations, the
|
|||
|
|
<code class="varname">outputHashAlgo</code> attribute is no longer mandatory
|
|||
|
|
if <code class="varname">outputHash</code> specifies the hash.</p><p><span class="command"><strong>nix hash-file</strong></span> and <span class="command"><strong>nix
|
|||
|
|
hash-path</strong></span> now print hashes in SRI format by
|
|||
|
|
default. They also use SHA-256 by default instead of SHA-512
|
|||
|
|
because that's what we use most of the time in Nixpkgs.</p></li><li class="listitem"><p>Integers are now 64 bits on all platforms.</p></li><li class="listitem"><p>The evaluator now prints profiling statistics (enabled via
|
|||
|
|
the <code class="envar">NIX_SHOW_STATS</code> and
|
|||
|
|
<code class="envar">NIX_COUNT_CALLS</code> environment variables) in JSON
|
|||
|
|
format.</p></li><li class="listitem"><p>The option <code class="option">--xml</code> in <span class="command"><strong>nix-store
|
|||
|
|
--query</strong></span> has been removed. Instead, there now is an
|
|||
|
|
option <code class="option">--graphml</code> to output the dependency graph
|
|||
|
|
in GraphML format.</p></li><li class="listitem"><p>All <code class="filename">nix-*</code> commands are now symlinks to
|
|||
|
|
<code class="filename">nix</code>. This saves a bit of disk space.</p></li><li class="listitem"><p><span class="command"><strong>nix repl</strong></span> now uses
|
|||
|
|
<code class="literal">libeditline</code> or
|
|||
|
|
<code class="literal">libreadline</code>.</p></li></ul></div></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a id="ssec-relnotes-2.1"></a>C.3. Release 2.1 (2018-09-02)</h2></div></div></div><p>This is primarily a bug fix release. It also reduces memory
|
|||
|
|
consumption in certain situations. In addition, it has the following
|
|||
|
|
new features:</p><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><p>The Nix installer will no longer default to the Multi-User
|
|||
|
|
installation for macOS. You can still <a class="link" href="#sect-multi-user-installation" title="4.2. Multi User Installation">instruct the installer to
|
|||
|
|
run in multi-user mode</a>.
|
|||
|
|
</p></li><li class="listitem"><p>The Nix installer now supports performing a Multi-User
|
|||
|
|
installation for Linux computers which are running systemd. You
|
|||
|
|
can <a class="link" href="#sect-multi-user-installation" title="4.2. Multi User Installation">select a Multi-User installation</a> by passing the
|
|||
|
|
<code class="option">--daemon</code> flag to the installer: <span class="command"><strong>sh <(curl
|
|||
|
|
https://nixos.org/nix/install) --daemon</strong></span>.
|
|||
|
|
</p><p>The multi-user installer cannot handle systems with SELinux.
|
|||
|
|
If your system has SELinux enabled, you can <a class="link" href="#sect-single-user-installation" title="4.1. Single User Installation">force the installer to run
|
|||
|
|
in single-user mode</a>.</p></li><li class="listitem"><p>New builtin functions:
|
|||
|
|
<code class="literal">builtins.bitAnd</code>,
|
|||
|
|
<code class="literal">builtins.bitOr</code>,
|
|||
|
|
<code class="literal">builtins.bitXor</code>,
|
|||
|
|
<code class="literal">builtins.fromTOML</code>,
|
|||
|
|
<code class="literal">builtins.concatMap</code>,
|
|||
|
|
<code class="literal">builtins.mapAttrs</code>.
|
|||
|
|
</p></li><li class="listitem"><p>The S3 binary cache store now supports uploading NARs larger
|
|||
|
|
than 5 GiB.</p></li><li class="listitem"><p>The S3 binary cache store now supports uploading to
|
|||
|
|
S3-compatible services with the <code class="literal">endpoint</code>
|
|||
|
|
option.</p></li><li class="listitem"><p>The flag <code class="option">--fallback</code> is no longer required
|
|||
|
|
to recover from disappeared NARs in binary caches.</p></li><li class="listitem"><p><span class="command"><strong>nix-daemon</strong></span> now respects
|
|||
|
|
<code class="option">--store</code>.</p></li><li class="listitem"><p><span class="command"><strong>nix run</strong></span> now respects
|
|||
|
|
<code class="varname">nix-support/propagated-user-env-packages</code>.</p></li></ul></div><p>This release has contributions from
|
|||
|
|
|
|||
|
|
Adrien Devresse,
|
|||
|
|
Aleksandr Pashkov,
|
|||
|
|
Alexandre Esteves,
|
|||
|
|
Amine Chikhaoui,
|
|||
|
|
Andrew Dunham,
|
|||
|
|
Asad Saeeduddin,
|
|||
|
|
aszlig,
|
|||
|
|
Ben Challenor,
|
|||
|
|
Ben Gamari,
|
|||
|
|
Benjamin Hipple,
|
|||
|
|
Bogdan Seniuc,
|
|||
|
|
Corey O'Connor,
|
|||
|
|
Daiderd Jordan,
|
|||
|
|
Daniel Peebles,
|
|||
|
|
Daniel Poelzleithner,
|
|||
|
|
Danylo Hlynskyi,
|
|||
|
|
Dmitry Kalinkin,
|
|||
|
|
Domen Kožar,
|
|||
|
|
Doug Beardsley,
|
|||
|
|
Eelco Dolstra,
|
|||
|
|
Erik Arvstedt,
|
|||
|
|
Félix Baylac-Jacqué,
|
|||
|
|
Gleb Peregud,
|
|||
|
|
Graham Christensen,
|
|||
|
|
Guillaume Maudoux,
|
|||
|
|
Ivan Kozik,
|
|||
|
|
John Arnold,
|
|||
|
|
Justin Humm,
|
|||
|
|
Linus Heckemann,
|
|||
|
|
Lorenzo Manacorda,
|
|||
|
|
Matthew Justin Bauer,
|
|||
|
|
Matthew O'Gorman,
|
|||
|
|
Maximilian Bosch,
|
|||
|
|
Michael Bishop,
|
|||
|
|
Michael Fiano,
|
|||
|
|
Michael Mercier,
|
|||
|
|
Michael Raskin,
|
|||
|
|
Michael Weiss,
|
|||
|
|
Nicolas Dudebout,
|
|||
|
|
Peter Simons,
|
|||
|
|
Ryan Trinkle,
|
|||
|
|
Samuel Dionne-Riel,
|
|||
|
|
Sean Seefried,
|
|||
|
|
Shea Levy,
|
|||
|
|
Symphorien Gibol,
|
|||
|
|
Tim Engler,
|
|||
|
|
Tim Sears,
|
|||
|
|
Tuomas Tynkkynen,
|
|||
|
|
volth,
|
|||
|
|
Will Dietz,
|
|||
|
|
Yorick van Pelt and
|
|||
|
|
zimbatm.
|
|||
|
|
</p></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a id="ssec-relnotes-2.0"></a>C.4. Release 2.0 (2018-02-22)</h2></div></div></div><p>The following incompatible changes have been made:</p><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><p>The manifest-based substituter mechanism
|
|||
|
|
(<span class="command"><strong>download-using-manifests</strong></span>) has been <a class="link" href="https://github.com/NixOS/nix/commit/867967265b80946dfe1db72d40324b4f9af988ed" target="_top">removed</a>. It
|
|||
|
|
has been superseded by the binary cache substituter mechanism
|
|||
|
|
since several years. As a result, the following programs have been
|
|||
|
|
removed:
|
|||
|
|
|
|||
|
|
</p><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: circle; "><li class="listitem"><p><span class="command"><strong>nix-pull</strong></span></p></li><li class="listitem"><p><span class="command"><strong>nix-generate-patches</strong></span></p></li><li class="listitem"><p><span class="command"><strong>bsdiff</strong></span></p></li><li class="listitem"><p><span class="command"><strong>bspatch</strong></span></p></li></ul></div><p>
|
|||
|
|
</p></li><li class="listitem"><p>The “copy from other stores” substituter mechanism
|
|||
|
|
(<span class="command"><strong>copy-from-other-stores</strong></span> and the
|
|||
|
|
<code class="envar">NIX_OTHER_STORES</code> environment variable) has been
|
|||
|
|
removed. It was primarily used by the NixOS installer to copy
|
|||
|
|
available paths from the installation medium. The replacement is
|
|||
|
|
to use a chroot store as a substituter
|
|||
|
|
(e.g. <code class="literal">--substituters /mnt</code>), or to build into a
|
|||
|
|
chroot store (e.g. <code class="literal">--store /mnt --substituters /</code>).</p></li><li class="listitem"><p>The command <span class="command"><strong>nix-push</strong></span> has been removed as
|
|||
|
|
part of the effort to eliminate Nix's dependency on Perl. You can
|
|||
|
|
use <span class="command"><strong>nix copy</strong></span> instead, e.g. <code class="literal">nix copy
|
|||
|
|
--to file:///tmp/my-binary-cache <em class="replaceable"><code>paths…</code></em></code></p></li><li class="listitem"><p>The “nested” log output feature (<code class="option">--log-type
|
|||
|
|
pretty</code>) has been removed. As a result,
|
|||
|
|
<span class="command"><strong>nix-log2xml</strong></span> was also removed.</p></li><li class="listitem"><p>OpenSSL-based signing has been <a class="link" href="https://github.com/NixOS/nix/commit/f435f8247553656774dd1b2c88e9de5d59cab203" target="_top">removed</a>. This
|
|||
|
|
feature was never well-supported. A better alternative is provided
|
|||
|
|
by the <code class="option">secret-key-files</code> and
|
|||
|
|
<code class="option">trusted-public-keys</code> options.</p></li><li class="listitem"><p>Failed build caching has been <a class="link" href="https://github.com/NixOS/nix/commit/8cffec84859cec8b610a2a22ab0c4d462a9351ff" target="_top">removed</a>. This
|
|||
|
|
feature was introduced to support the Hydra continuous build
|
|||
|
|
system, but Hydra no longer uses it.</p></li><li class="listitem"><p><code class="filename">nix-mode.el</code> has been removed from
|
|||
|
|
Nix. It is now <a class="link" href="https://github.com/NixOS/nix-mode" target="_top">a separate
|
|||
|
|
repository</a> and can be installed through the MELPA package
|
|||
|
|
repository.</p></li></ul></div><p>This release has the following new features:</p><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><p>It introduces a new command named <span class="command"><strong>nix</strong></span>,
|
|||
|
|
which is intended to eventually replace all
|
|||
|
|
<span class="command"><strong>nix-*</strong></span> commands with a more consistent and
|
|||
|
|
better designed user interface. It currently provides replacements
|
|||
|
|
for some (but not all) of the functionality provided by
|
|||
|
|
<span class="command"><strong>nix-store</strong></span>, <span class="command"><strong>nix-build</strong></span>,
|
|||
|
|
<span class="command"><strong>nix-shell -p</strong></span>, <span class="command"><strong>nix-env -qa</strong></span>,
|
|||
|
|
<span class="command"><strong>nix-instantiate --eval</strong></span>,
|
|||
|
|
<span class="command"><strong>nix-push</strong></span> and
|
|||
|
|
<span class="command"><strong>nix-copy-closure</strong></span>. It has the following major
|
|||
|
|
features:</p><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: circle; "><li class="listitem"><p>Unlike the legacy commands, it has a consistent way to
|
|||
|
|
refer to packages and package-like arguments (like store
|
|||
|
|
paths). For example, the following commands all copy the GNU
|
|||
|
|
Hello package to a remote machine:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">nix copy --to ssh://machine nixpkgs.hello</pre><p>
|
|||
|
|
</p><pre class="screen">nix copy --to ssh://machine /nix/store/0i2jd68mp5g6h2sa5k9c85rb80sn8hi9-hello-2.10</pre><p>
|
|||
|
|
</p><pre class="screen">nix copy --to ssh://machine '(with import <nixpkgs> {}; hello)'</pre><p>
|
|||
|
|
|
|||
|
|
By contrast, <span class="command"><strong>nix-copy-closure</strong></span> only accepted
|
|||
|
|
store paths as arguments.</p></li><li class="listitem"><p>It is self-documenting: <code class="option">--help</code> shows
|
|||
|
|
all available command-line arguments. If
|
|||
|
|
<code class="option">--help</code> is given after a subcommand, it shows
|
|||
|
|
examples for that subcommand. <span class="command"><strong>nix
|
|||
|
|
--help-config</strong></span> shows all configuration
|
|||
|
|
options.</p></li><li class="listitem"><p>It is much less verbose. By default, it displays a
|
|||
|
|
single-line progress indicator that shows how many packages
|
|||
|
|
are left to be built or downloaded, and (if there are running
|
|||
|
|
builds) the most recent line of builder output. If a build
|
|||
|
|
fails, it shows the last few lines of builder output. The full
|
|||
|
|
build log can be retrieved using <span class="command"><strong>nix
|
|||
|
|
log</strong></span>.</p></li><li class="listitem"><p>It <a class="link" href="https://github.com/NixOS/nix/commit/b8283773bd64d7da6859ed520ee19867742a03ba" target="_top">provides</a>
|
|||
|
|
all <code class="filename">nix.conf</code> configuration options as
|
|||
|
|
command line flags. For example, instead of <code class="literal">--option
|
|||
|
|
http-connections 100</code> you can write
|
|||
|
|
<code class="literal">--http-connections 100</code>. Boolean options can
|
|||
|
|
be written as
|
|||
|
|
<code class="literal">--<em class="replaceable"><code>foo</code></em></code> or
|
|||
|
|
<code class="literal">--no-<em class="replaceable"><code>foo</code></em></code>
|
|||
|
|
(e.g. <code class="option">--no-auto-optimise-store</code>).</p></li><li class="listitem"><p>Many subcommands have a <code class="option">--json</code> flag to
|
|||
|
|
write results to stdout in JSON format.</p></li></ul></div><div class="warning"><h3 class="title">Warning</h3><p>Please note that the <span class="command"><strong>nix</strong></span> command
|
|||
|
|
is a work in progress and the interface is subject to
|
|||
|
|
change.</p></div><p>It provides the following high-level (“porcelain”)
|
|||
|
|
subcommands:</p><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: circle; "><li class="listitem"><p><span class="command"><strong>nix build</strong></span> is a replacement for
|
|||
|
|
<span class="command"><strong>nix-build</strong></span>.</p></li><li class="listitem"><p><span class="command"><strong>nix run</strong></span> executes a command in an
|
|||
|
|
environment in which the specified packages are available. It
|
|||
|
|
is (roughly) a replacement for <span class="command"><strong>nix-shell
|
|||
|
|
-p</strong></span>. Unlike that command, it does not execute the
|
|||
|
|
command in a shell, and has a flag (<span class="command"><strong>-c</strong></span>)
|
|||
|
|
that specifies the unquoted command line to be
|
|||
|
|
executed.</p><p>It is particularly useful in conjunction with chroot
|
|||
|
|
stores, allowing Linux users who do not have permission to
|
|||
|
|
install Nix in <span class="command"><strong>/nix/store</strong></span> to still use
|
|||
|
|
binary substitutes that assume
|
|||
|
|
<span class="command"><strong>/nix/store</strong></span>. For example,
|
|||
|
|
|
|||
|
|
</p><pre class="screen">nix run --store ~/my-nix nixpkgs.hello -c hello --greeting 'Hi everybody!'</pre><p>
|
|||
|
|
|
|||
|
|
downloads (or if not substitutes are available, builds) the
|
|||
|
|
GNU Hello package into
|
|||
|
|
<code class="filename">~/my-nix/nix/store</code>, then runs
|
|||
|
|
<span class="command"><strong>hello</strong></span> in a mount namespace where
|
|||
|
|
<code class="filename">~/my-nix/nix/store</code> is mounted onto
|
|||
|
|
<span class="command"><strong>/nix/store</strong></span>.</p></li><li class="listitem"><p><span class="command"><strong>nix search</strong></span> replaces <span class="command"><strong>nix-env
|
|||
|
|
-qa</strong></span>. It searches the available packages for
|
|||
|
|
occurrences of a search string in the attribute name, package
|
|||
|
|
name or description. Unlike <span class="command"><strong>nix-env -qa</strong></span>, it
|
|||
|
|
has a cache to speed up subsequent searches.</p></li><li class="listitem"><p><span class="command"><strong>nix copy</strong></span> copies paths between
|
|||
|
|
arbitrary Nix stores, generalising
|
|||
|
|
<span class="command"><strong>nix-copy-closure</strong></span> and
|
|||
|
|
<span class="command"><strong>nix-push</strong></span>.</p></li><li class="listitem"><p><span class="command"><strong>nix repl</strong></span> replaces the external
|
|||
|
|
program <span class="command"><strong>nix-repl</strong></span>. It provides an
|
|||
|
|
interactive environment for evaluating and building Nix
|
|||
|
|
expressions. Note that it uses <code class="literal">linenoise-ng</code>
|
|||
|
|
instead of GNU Readline.</p></li><li class="listitem"><p><span class="command"><strong>nix upgrade-nix</strong></span> upgrades Nix to the
|
|||
|
|
latest stable version. This requires that Nix is installed in
|
|||
|
|
a profile. (Thus it won’t work on NixOS, or if it’s installed
|
|||
|
|
outside of the Nix store.)</p></li><li class="listitem"><p><span class="command"><strong>nix verify</strong></span> checks whether store paths
|
|||
|
|
are unmodified and/or “trusted” (see below). It replaces
|
|||
|
|
<span class="command"><strong>nix-store --verify</strong></span> and <span class="command"><strong>nix-store
|
|||
|
|
--verify-path</strong></span>.</p></li><li class="listitem"><p><span class="command"><strong>nix log</strong></span> shows the build log of a
|
|||
|
|
package or path. If the build log is not available locally, it
|
|||
|
|
will try to obtain it from the configured substituters (such
|
|||
|
|
as <code class="uri">cache.nixos.org</code>, which now provides build
|
|||
|
|
logs).</p></li><li class="listitem"><p><span class="command"><strong>nix edit</strong></span> opens the source code of a
|
|||
|
|
package in your editor.</p></li><li class="listitem"><p><span class="command"><strong>nix eval</strong></span> replaces
|
|||
|
|
<span class="command"><strong>nix-instantiate --eval</strong></span>.</p></li><li class="listitem"><p><span class="command"><strong><a class="command" href="https://github.com/NixOS/nix/commit/d41c5eb13f4f3a37d80dbc6d3888644170c3b44a" target="_top">nix
|
|||
|
|
why-depends</a></strong></span> shows why one store path has another in
|
|||
|
|
its closure. This is primarily useful to finding the causes of
|
|||
|
|
closure bloat. For example,
|
|||
|
|
|
|||
|
|
</p><pre class="screen">nix why-depends nixpkgs.vlc nixpkgs.libdrm.dev</pre><p>
|
|||
|
|
|
|||
|
|
shows a chain of files and fragments of file contents that
|
|||
|
|
cause the VLC package to have the “dev” output of
|
|||
|
|
<code class="literal">libdrm</code> in its closure — an undesirable
|
|||
|
|
situation.</p></li><li class="listitem"><p><span class="command"><strong>nix path-info</strong></span> shows information about
|
|||
|
|
store paths, replacing <span class="command"><strong>nix-store -q</strong></span>. A
|
|||
|
|
useful feature is the option <code class="option">--closure-size</code>
|
|||
|
|
(<code class="option">-S</code>). For example, the following command show
|
|||
|
|
the closure sizes of every path in the current NixOS system
|
|||
|
|
closure, sorted by size:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">nix path-info -rS /run/current-system | sort -nk2</pre><p>
|
|||
|
|
|
|||
|
|
</p></li><li class="listitem"><p><span class="command"><strong>nix optimise-store</strong></span> replaces
|
|||
|
|
<span class="command"><strong>nix-store --optimise</strong></span>. The main difference
|
|||
|
|
is that it has a progress indicator.</p></li></ul></div><p>A number of low-level (“plumbing”) commands are also
|
|||
|
|
available:</p><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: circle; "><li class="listitem"><p><span class="command"><strong>nix ls-store</strong></span> and <span class="command"><strong>nix
|
|||
|
|
ls-nar</strong></span> list the contents of a store path or NAR
|
|||
|
|
file. The former is primarily useful in conjunction with
|
|||
|
|
remote stores, e.g.
|
|||
|
|
|
|||
|
|
</p><pre class="screen">nix ls-store --store https://cache.nixos.org/ -lR /nix/store/0i2jd68mp5g6h2sa5k9c85rb80sn8hi9-hello-2.10</pre><p>
|
|||
|
|
|
|||
|
|
lists the contents of path in a binary cache.</p></li><li class="listitem"><p><span class="command"><strong>nix cat-store</strong></span> and <span class="command"><strong>nix
|
|||
|
|
cat-nar</strong></span> allow extracting a file from a store path or
|
|||
|
|
NAR file.</p></li><li class="listitem"><p><span class="command"><strong>nix dump-path</strong></span> writes the contents of
|
|||
|
|
a store path to stdout in NAR format. This replaces
|
|||
|
|
<span class="command"><strong>nix-store --dump</strong></span>.</p></li><li class="listitem"><p><span class="command"><strong><a class="command" href="https://github.com/NixOS/nix/commit/e8d6ee7c1b90a2fe6d824f1a875acc56799ae6e2" target="_top">nix
|
|||
|
|
show-derivation</a></strong></span> displays a store derivation in JSON
|
|||
|
|
format. This is an alternative to
|
|||
|
|
<span class="command"><strong>pp-aterm</strong></span>.</p></li><li class="listitem"><p><span class="command"><strong><a class="command" href="https://github.com/NixOS/nix/commit/970366266b8df712f5f9cedb45af183ef5a8357f" target="_top">nix
|
|||
|
|
add-to-store</a></strong></span> replaces <span class="command"><strong>nix-store
|
|||
|
|
--add</strong></span>.</p></li><li class="listitem"><p><span class="command"><strong>nix sign-paths</strong></span> signs store
|
|||
|
|
paths.</p></li><li class="listitem"><p><span class="command"><strong>nix copy-sigs</strong></span> copies signatures from
|
|||
|
|
one store to another.</p></li><li class="listitem"><p><span class="command"><strong>nix show-config</strong></span> shows all
|
|||
|
|
configuration options and their current values.</p></li></ul></div></li><li class="listitem"><p>The store abstraction that Nix has had for a long time to
|
|||
|
|
support store access via the Nix daemon has been extended
|
|||
|
|
significantly. In particular, substituters (which used to be
|
|||
|
|
external programs such as
|
|||
|
|
<span class="command"><strong>download-from-binary-cache</strong></span>) are now subclasses
|
|||
|
|
of the abstract <code class="classname">Store</code> class. This allows
|
|||
|
|
many Nix commands to operate on such store types. For example,
|
|||
|
|
<span class="command"><strong>nix path-info</strong></span> shows information about paths in
|
|||
|
|
your local Nix store, while <span class="command"><strong>nix path-info --store
|
|||
|
|
https://cache.nixos.org/</strong></span> shows information about paths
|
|||
|
|
in the specified binary cache. Similarly,
|
|||
|
|
<span class="command"><strong>nix-copy-closure</strong></span>, <span class="command"><strong>nix-push</strong></span>
|
|||
|
|
and substitution are all instances of the general notion of
|
|||
|
|
copying paths between different kinds of Nix stores.</p><p>Stores are specified using an URI-like syntax,
|
|||
|
|
e.g. <code class="uri">https://cache.nixos.org/</code> or
|
|||
|
|
<code class="uri">ssh://machine</code>. The following store types are supported:
|
|||
|
|
|
|||
|
|
</p><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: circle; "><li class="listitem"><p><code class="classname">LocalStore</code> (stori URI
|
|||
|
|
<code class="literal">local</code> or an absolute path) and the misnamed
|
|||
|
|
<code class="classname">RemoteStore</code> (<code class="literal">daemon</code>)
|
|||
|
|
provide access to a local Nix store, the latter via the Nix
|
|||
|
|
daemon. You can use <code class="literal">auto</code> or the empty
|
|||
|
|
string to auto-select a local or daemon store depending on
|
|||
|
|
whether you have write permission to the Nix store. It is no
|
|||
|
|
longer necessary to set the <code class="envar">NIX_REMOTE</code>
|
|||
|
|
environment variable to use the Nix daemon.</p><p>As noted above, <code class="classname">LocalStore</code> now
|
|||
|
|
supports chroot builds, allowing the “physical” location of
|
|||
|
|
the Nix store
|
|||
|
|
(e.g. <code class="filename">/home/alice/nix/store</code>) to differ
|
|||
|
|
from its “logical” location (typically
|
|||
|
|
<code class="filename">/nix/store</code>). This allows non-root users
|
|||
|
|
to use Nix while still getting the benefits from prebuilt
|
|||
|
|
binaries from <code class="uri">cache.nixos.org</code>.</p></li><li class="listitem"><p><code class="classname">BinaryCacheStore</code> is the abstract
|
|||
|
|
superclass of all binary cache stores. It supports writing
|
|||
|
|
build logs and NAR content listings in JSON format.</p></li><li class="listitem"><p><code class="classname">HttpBinaryCacheStore</code>
|
|||
|
|
(<code class="literal">http://</code>, <code class="literal">https://</code>)
|
|||
|
|
supports binary caches via HTTP or HTTPS. If the server
|
|||
|
|
supports <code class="literal">PUT</code> requests, it supports
|
|||
|
|
uploading store paths via commands such as <span class="command"><strong>nix
|
|||
|
|
copy</strong></span>.</p></li><li class="listitem"><p><code class="classname">LocalBinaryCacheStore</code>
|
|||
|
|
(<code class="literal">file://</code>) supports binary caches in the
|
|||
|
|
local filesystem.</p></li><li class="listitem"><p><code class="classname">S3BinaryCacheStore</code>
|
|||
|
|
(<code class="literal">s3://</code>) supports binary caches stored in
|
|||
|
|
Amazon S3, if enabled at compile time.</p></li><li class="listitem"><p><code class="classname">LegacySSHStore</code> (<code class="literal">ssh://</code>)
|
|||
|
|
is used to implement remote builds and
|
|||
|
|
<span class="command"><strong>nix-copy-closure</strong></span>.</p></li><li class="listitem"><p><code class="classname">SSHStore</code>
|
|||
|
|
(<code class="literal">ssh-ng://</code>) supports arbitrary Nix
|
|||
|
|
operations on a remote machine via the same protocol used by
|
|||
|
|
<span class="command"><strong>nix-daemon</strong></span>.</p></li></ul></div><p>
|
|||
|
|
|
|||
|
|
</p></li><li class="listitem"><p>Security has been improved in various ways:
|
|||
|
|
|
|||
|
|
</p><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: circle; "><li class="listitem"><p>Nix now stores signatures for local store
|
|||
|
|
paths. When paths are copied between stores (e.g., copied from
|
|||
|
|
a binary cache to a local store), signatures are
|
|||
|
|
propagated.</p><p>Locally-built paths are signed automatically using the
|
|||
|
|
secret keys specified by the <code class="option">secret-key-files</code>
|
|||
|
|
store option. Secret/public key pairs can be generated using
|
|||
|
|
<span class="command"><strong>nix-store
|
|||
|
|
--generate-binary-cache-key</strong></span>.</p><p>In addition, locally-built store paths are marked as
|
|||
|
|
“ultimately trusted”, but this bit is not propagated when
|
|||
|
|
paths are copied between stores.</p></li><li class="listitem"><p>Content-addressable store paths no longer require
|
|||
|
|
signatures — they can be imported into a store by unprivileged
|
|||
|
|
users even if they lack signatures.</p></li><li class="listitem"><p>The command <span class="command"><strong>nix verify</strong></span> checks whether
|
|||
|
|
the specified paths are trusted, i.e., have a certain number
|
|||
|
|
of trusted signatures, are ultimately trusted, or are
|
|||
|
|
content-addressed.</p></li><li class="listitem"><p>Substitutions from binary caches <a class="link" href="https://github.com/NixOS/nix/commit/ecbc3fedd3d5bdc5a0e1a0a51b29062f2874ac8b" target="_top">now</a>
|
|||
|
|
require signatures by default. This was already the case on
|
|||
|
|
NixOS.</p></li><li class="listitem"><p>In Linux sandbox builds, we <a class="link" href="https://github.com/NixOS/nix/commit/eba840c8a13b465ace90172ff76a0db2899ab11b" target="_top">now</a>
|
|||
|
|
use <code class="filename">/build</code> instead of
|
|||
|
|
<code class="filename">/tmp</code> as the temporary build
|
|||
|
|
directory. This fixes potential security problems when a build
|
|||
|
|
accidentally stores its <code class="envar">TMPDIR</code> in some
|
|||
|
|
security-sensitive place, such as an RPATH.</p></li></ul></div><p>
|
|||
|
|
|
|||
|
|
</p></li><li class="listitem"><p><span class="emphasis"><em>Pure evaluation mode</em></span>. With the
|
|||
|
|
<code class="literal">--pure-eval</code> flag, Nix enables a variant of the existing
|
|||
|
|
restricted evaluation mode that forbids access to anything that could cause
|
|||
|
|
different evaluations of the same command line arguments to produce a
|
|||
|
|
different result. This includes builtin functions such as
|
|||
|
|
<code class="function">builtins.getEnv</code>, but more importantly,
|
|||
|
|
<span class="emphasis"><em>all</em></span> filesystem or network access unless a content hash
|
|||
|
|
or commit hash is specified. For example, calls to
|
|||
|
|
<code class="function">builtins.fetchGit</code> are only allowed if a
|
|||
|
|
<code class="varname">rev</code> attribute is specified.</p><p>The goal of this feature is to enable true reproducibility
|
|||
|
|
and traceability of builds (including NixOS system configurations)
|
|||
|
|
at the evaluation level. For example, in the future,
|
|||
|
|
<span class="command"><strong>nixos-rebuild</strong></span> might build configurations from a
|
|||
|
|
Nix expression in a Git repository in pure mode. That expression
|
|||
|
|
might fetch other repositories such as Nixpkgs via
|
|||
|
|
<code class="function">builtins.fetchGit</code>. The commit hash of the
|
|||
|
|
top-level repository then uniquely identifies a running system,
|
|||
|
|
and, in conjunction with that repository, allows it to be
|
|||
|
|
reproduced or modified.</p></li><li class="listitem"><p>There are several new features to support binary
|
|||
|
|
reproducibility (i.e. to help ensure that multiple builds of the
|
|||
|
|
same derivation produce exactly the same output). When
|
|||
|
|
<code class="option">enforce-determinism</code> is set to
|
|||
|
|
<code class="literal">false</code>, it’s <a class="link" href="https://github.com/NixOS/nix/commit/8bdf83f936adae6f2c907a6d2541e80d4120f051" target="_top">no
|
|||
|
|
longer</a> a fatal error if build rounds produce different
|
|||
|
|
output. Also, a hook named <code class="option">diff-hook</code> is <a class="link" href="https://github.com/NixOS/nix/commit/9a313469a4bdea2d1e8df24d16289dc2a172a169" target="_top">provided</a>
|
|||
|
|
to allow you to run tools such as <span class="command"><strong>diffoscope</strong></span>
|
|||
|
|
when build rounds produce different output.</p></li><li class="listitem"><p>Configuring remote builds is a lot easier now. Provided you
|
|||
|
|
are not using the Nix daemon, you can now just specify a remote
|
|||
|
|
build machine on the command line, e.g. <code class="literal">--option builders
|
|||
|
|
'ssh://my-mac x86_64-darwin'</code>. The environment variable
|
|||
|
|
<code class="envar">NIX_BUILD_HOOK</code> has been removed and is no longer
|
|||
|
|
needed. The environment variable <code class="envar">NIX_REMOTE_SYSTEMS</code>
|
|||
|
|
is still supported for compatibility, but it is also possible to
|
|||
|
|
specify builders in <span class="command"><strong>nix.conf</strong></span> by setting the
|
|||
|
|
option <code class="literal">builders =
|
|||
|
|
@<em class="replaceable"><code>path</code></em></code>.</p></li><li class="listitem"><p>If a fixed-output derivation produces a result with an
|
|||
|
|
incorrect hash, the output path is moved to the location
|
|||
|
|
corresponding to the actual hash and registered as valid. Thus, a
|
|||
|
|
subsequent build of the fixed-output derivation with the correct
|
|||
|
|
hash is unnecessary.</p></li><li class="listitem"><p><span class="command"><strong>nix-shell</strong></span> <a class="link" href="https://github.com/NixOS/nix/commit/ea59f39326c8e9dc42dfed4bcbf597fbce58797c" target="_top">now</a>
|
|||
|
|
sets the <code class="varname">IN_NIX_SHELL</code> environment variable
|
|||
|
|
during evaluation and in the shell itself. This can be used to
|
|||
|
|
perform different actions depending on whether you’re in a Nix
|
|||
|
|
shell or in a regular build. Nixpkgs provides
|
|||
|
|
<code class="varname">lib.inNixShell</code> to check this variable during
|
|||
|
|
evaluation.</p></li><li class="listitem"><p><code class="envar">NIX_PATH</code> is now lazy, so URIs in the path are
|
|||
|
|
only downloaded if they are needed for evaluation.</p></li><li class="listitem"><p>You can now use
|
|||
|
|
<code class="uri">channel:<em class="replaceable"><code>channel-name</code></em></code> as a
|
|||
|
|
short-hand for
|
|||
|
|
<code class="uri">https://nixos.org/channels/<em class="replaceable"><code>channel-name</code></em>/nixexprs.tar.xz</code>. For
|
|||
|
|
example, <code class="literal">nix-build channel:nixos-15.09 -A hello</code>
|
|||
|
|
will build the GNU Hello package from the
|
|||
|
|
<code class="literal">nixos-15.09</code> channel. In the future, this may
|
|||
|
|
use Git to fetch updates more efficiently.</p></li><li class="listitem"><p>When <code class="option">--no-build-output</code> is given, the last
|
|||
|
|
10 lines of the build log will be shown if a build
|
|||
|
|
fails.</p></li><li class="listitem"><p>Networking has been improved:
|
|||
|
|
|
|||
|
|
</p><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: circle; "><li class="listitem"><p>HTTP/2 is now supported. This makes binary cache lookups
|
|||
|
|
<a class="link" href="https://github.com/NixOS/nix/commit/90ad02bf626b885a5dd8967894e2eafc953bdf92" target="_top">much
|
|||
|
|
more efficient</a>.</p></li><li class="listitem"><p>We now retry downloads on many HTTP errors, making
|
|||
|
|
binary caches substituters more resilient to temporary
|
|||
|
|
failures.</p></li><li class="listitem"><p>HTTP credentials can now be configured via the standard
|
|||
|
|
<code class="filename">netrc</code> mechanism.</p></li><li class="listitem"><p>If S3 support is enabled at compile time,
|
|||
|
|
<code class="uri">s3://</code> URIs are <a class="link" href="https://github.com/NixOS/nix/commit/9ff9c3f2f80ba4108e9c945bbfda2c64735f987b" target="_top">supported</a>
|
|||
|
|
in all places where Nix allows URIs.</p></li><li class="listitem"><p>Brotli compression is now supported. In particular,
|
|||
|
|
<code class="uri">cache.nixos.org</code> build logs are now compressed using
|
|||
|
|
Brotli.</p></li></ul></div><p>
|
|||
|
|
|
|||
|
|
</p></li><li class="listitem"><p><span class="command"><strong>nix-env</strong></span> <a class="link" href="https://github.com/NixOS/nix/commit/b0cb11722626e906a73f10dd9a0c9eea29faf43a" target="_top">now</a>
|
|||
|
|
ignores packages with bad derivation names (in particular those
|
|||
|
|
starting with a digit or containing a dot).</p></li><li class="listitem"><p>Many configuration options have been renamed, either because
|
|||
|
|
they were unnecessarily verbose
|
|||
|
|
(e.g. <code class="option">build-use-sandbox</code> is now just
|
|||
|
|
<code class="option">sandbox</code>) or to reflect generalised behaviour
|
|||
|
|
(e.g. <code class="option">binary-caches</code> is now
|
|||
|
|
<code class="option">substituters</code> because it allows arbitrary store
|
|||
|
|
URIs). The old names are still supported for compatibility.</p></li><li class="listitem"><p>The <code class="option">max-jobs</code> option can <a class="link" href="https://github.com/NixOS/nix/commit/7251d048fa812d2551b7003bc9f13a8f5d4c95a5" target="_top">now</a>
|
|||
|
|
be set to <code class="literal">auto</code> to use the number of CPUs in the
|
|||
|
|
system.</p></li><li class="listitem"><p>Hashes can <a class="link" href="https://github.com/NixOS/nix/commit/c0015e87af70f539f24d2aa2bc224a9d8b84276b" target="_top">now</a>
|
|||
|
|
be specified in base-64 format, in addition to base-16 and the
|
|||
|
|
non-standard base-32.</p></li><li class="listitem"><p><span class="command"><strong>nix-shell</strong></span> now uses
|
|||
|
|
<code class="varname">bashInteractive</code> from Nixpkgs, rather than the
|
|||
|
|
<span class="command"><strong>bash</strong></span> command that happens to be in the caller’s
|
|||
|
|
<code class="envar">PATH</code>. This is especially important on macOS where
|
|||
|
|
the <span class="command"><strong>bash</strong></span> provided by the system is seriously
|
|||
|
|
outdated and cannot execute <code class="literal">stdenv</code>’s setup
|
|||
|
|
script.</p></li><li class="listitem"><p>Nix can now automatically trigger a garbage collection if
|
|||
|
|
free disk space drops below a certain level during a build. This
|
|||
|
|
is configured using the <code class="option">min-free</code> and
|
|||
|
|
<code class="option">max-free</code> options.</p></li><li class="listitem"><p><span class="command"><strong>nix-store -q --roots</strong></span> and
|
|||
|
|
<span class="command"><strong>nix-store --gc --print-roots</strong></span> now show temporary
|
|||
|
|
and in-memory roots.</p></li><li class="listitem"><p>
|
|||
|
|
Nix can now be extended with plugins. See the documentation of
|
|||
|
|
the <code class="option">plugin-files</code> option for more details.
|
|||
|
|
</p></li></ul></div><p>The Nix language has the following new features:
|
|||
|
|
|
|||
|
|
</p><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><p>It supports floating point numbers. They are based on the
|
|||
|
|
C++ <code class="literal">float</code> type and are supported by the
|
|||
|
|
existing numerical operators. Export and import to and from JSON
|
|||
|
|
and XML works, too.</p></li><li class="listitem"><p>Derivation attributes can now reference the outputs of the
|
|||
|
|
derivation using the <code class="function">placeholder</code> builtin
|
|||
|
|
function. For example, the attribute
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
configureFlags = "--prefix=${placeholder "out"} --includedir=${placeholder "dev"}";
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
will cause the <code class="envar">configureFlags</code> environment variable
|
|||
|
|
to contain the actual store paths corresponding to the
|
|||
|
|
<code class="literal">out</code> and <code class="literal">dev</code> outputs.</p></li></ul></div><p>
|
|||
|
|
|
|||
|
|
</p><p>The following builtin functions are new or extended:
|
|||
|
|
|
|||
|
|
</p><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><p><code class="function"><a class="function" href="https://github.com/NixOS/nix/commit/38539b943a060d9cdfc24d6e5d997c0885b8aa2f" target="_top">builtins.fetchGit</a></code>
|
|||
|
|
allows Git repositories to be fetched at evaluation time. Thus it
|
|||
|
|
differs from the <code class="function">fetchgit</code> function in
|
|||
|
|
Nixpkgs, which fetches at build time and cannot be used to fetch
|
|||
|
|
Nix expressions during evaluation. A typical use case is to import
|
|||
|
|
external NixOS modules from your configuration, e.g.
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">imports = [ (builtins.fetchGit https://github.com/edolstra/dwarffs + "/module.nix") ];</pre><p>
|
|||
|
|
|
|||
|
|
</p></li><li class="listitem"><p>Similarly, <code class="function">builtins.fetchMercurial</code>
|
|||
|
|
allows you to fetch Mercurial repositories.</p></li><li class="listitem"><p><code class="function">builtins.path</code> generalises
|
|||
|
|
<code class="function">builtins.filterSource</code> and path literals
|
|||
|
|
(e.g. <code class="literal">./foo</code>). It allows specifying a store path
|
|||
|
|
name that differs from the source path name
|
|||
|
|
(e.g. <code class="literal">builtins.path { path = ./foo; name = "bar";
|
|||
|
|
}</code>) and also supports filtering out unwanted
|
|||
|
|
files.</p></li><li class="listitem"><p><code class="function">builtins.fetchurl</code> and
|
|||
|
|
<code class="function">builtins.fetchTarball</code> now support
|
|||
|
|
<code class="varname">sha256</code> and <code class="varname">name</code>
|
|||
|
|
attributes.</p></li><li class="listitem"><p><code class="function"><a class="function" href="https://github.com/NixOS/nix/commit/b8867a0239b1930a16f9ef3f7f3e864b01416dff" target="_top">builtins.split</a></code>
|
|||
|
|
splits a string using a POSIX extended regular expression as the
|
|||
|
|
separator.</p></li><li class="listitem"><p><code class="function"><a class="function" href="https://github.com/NixOS/nix/commit/26d92017d3b36cff940dcb7d1611c42232edb81a" target="_top">builtins.partition</a></code>
|
|||
|
|
partitions the elements of a list into two lists, depending on a
|
|||
|
|
Boolean predicate.</p></li><li class="listitem"><p><code class="literal"><nix/fetchurl.nix></code> now uses the
|
|||
|
|
content-addressable tarball cache at
|
|||
|
|
<code class="uri">http://tarballs.nixos.org/</code>, just like
|
|||
|
|
<code class="function">fetchurl</code> in
|
|||
|
|
Nixpkgs. (f2682e6e18a76ecbfb8a12c17e3a0ca15c084197)</p></li><li class="listitem"><p>In restricted and pure evaluation mode, builtin functions
|
|||
|
|
that download from the network (such as
|
|||
|
|
<code class="function">fetchGit</code>) are permitted to fetch underneath a
|
|||
|
|
list of URI prefixes specified in the option
|
|||
|
|
<code class="option">allowed-uris</code>.</p></li></ul></div><p>
|
|||
|
|
|
|||
|
|
</p><p>The Nix build environment has the following changes:
|
|||
|
|
|
|||
|
|
</p><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><p>Values such as Booleans, integers, (nested) lists and
|
|||
|
|
attribute sets can <a class="link" href="https://github.com/NixOS/nix/commit/6de33a9c675b187437a2e1abbcb290981a89ecb1" target="_top">now</a>
|
|||
|
|
be passed to builders in a non-lossy way. If the special attribute
|
|||
|
|
<code class="varname">__structuredAttrs</code> is set to
|
|||
|
|
<code class="literal">true</code>, the other derivation attributes are
|
|||
|
|
serialised in JSON format and made available to the builder via
|
|||
|
|
the file <code class="envar">.attrs.json</code> in the builder’s temporary
|
|||
|
|
directory. This obviates the need for
|
|||
|
|
<code class="varname">passAsFile</code> since JSON files have no size
|
|||
|
|
restrictions, unlike process environments.</p><p><a class="link" href="https://github.com/NixOS/nix/commit/2d5b1b24bf70a498e4c0b378704cfdb6471cc699" target="_top">As
|
|||
|
|
a convenience to Bash builders</a>, Nix writes a script named
|
|||
|
|
<code class="envar">.attrs.sh</code> to the builder’s directory that
|
|||
|
|
initialises shell variables corresponding to all attributes that
|
|||
|
|
are representable in Bash. This includes non-nested (associative)
|
|||
|
|
arrays. For example, the attribute <code class="literal">hardening.format =
|
|||
|
|
true</code> ends up as the Bash associative array element
|
|||
|
|
<code class="literal">${hardening[format]}</code>.</p></li><li class="listitem"><p>Builders can <a class="link" href="https://github.com/NixOS/nix/commit/88e6bb76de5564b3217be9688677d1c89101b2a3" target="_top">now</a>
|
|||
|
|
communicate what build phase they are in by writing messages to
|
|||
|
|
the file descriptor specified in <code class="envar">NIX_LOG_FD</code>. The
|
|||
|
|
current phase is shown by the <span class="command"><strong>nix</strong></span> progress
|
|||
|
|
indicator.
|
|||
|
|
</p></li><li class="listitem"><p>In Linux sandbox builds, we <a class="link" href="https://github.com/NixOS/nix/commit/a2d92bb20e82a0957067ede60e91fab256948b41" target="_top">now</a>
|
|||
|
|
provide a default <code class="filename">/bin/sh</code> (namely
|
|||
|
|
<code class="filename">ash</code> from BusyBox).</p></li><li class="listitem"><p>In structured attribute mode,
|
|||
|
|
<code class="varname">exportReferencesGraph</code> <a class="link" href="https://github.com/NixOS/nix/commit/c2b0d8749f7e77afc1c4b3e8dd36b7ee9720af4a" target="_top">exports</a>
|
|||
|
|
extended information about closures in JSON format. In particular,
|
|||
|
|
it includes the sizes and hashes of paths. This is primarily
|
|||
|
|
useful for NixOS image builders.</p></li><li class="listitem"><p>Builds are <a class="link" href="https://github.com/NixOS/nix/commit/21948deed99a3295e4d5666e027a6ca42dc00b40" target="_top">now</a>
|
|||
|
|
killed as soon as Nix receives EOF on the builder’s stdout or
|
|||
|
|
stderr. This fixes a bug that allowed builds to hang Nix
|
|||
|
|
indefinitely, regardless of
|
|||
|
|
timeouts.</p></li><li class="listitem"><p>The <code class="option">sandbox-paths</code> configuration
|
|||
|
|
option can now specify optional paths by appending a
|
|||
|
|
<code class="literal">?</code>, e.g. <code class="literal">/dev/nvidiactl?</code> will
|
|||
|
|
bind-mount <code class="varname">/dev/nvidiactl</code> only if it
|
|||
|
|
exists.</p></li><li class="listitem"><p>On Linux, builds are now executed in a user
|
|||
|
|
namespace with UID 1000 and GID 100.</p></li></ul></div><p>
|
|||
|
|
|
|||
|
|
</p><p>A number of significant internal changes were made:
|
|||
|
|
|
|||
|
|
</p><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><p>Nix no longer depends on Perl and all Perl components have
|
|||
|
|
been rewritten in C++ or removed. The Perl bindings that used to
|
|||
|
|
be part of Nix have been moved to a separate package,
|
|||
|
|
<code class="literal">nix-perl</code>.</p></li><li class="listitem"><p>All <code class="classname">Store</code> classes are now
|
|||
|
|
thread-safe. <code class="classname">RemoteStore</code> supports multiple
|
|||
|
|
concurrent connections to the daemon. This is primarily useful in
|
|||
|
|
multi-threaded programs such as
|
|||
|
|
<span class="command"><strong>hydra-queue-runner</strong></span>.</p></li></ul></div><p>
|
|||
|
|
|
|||
|
|
</p><p>This release has contributions from
|
|||
|
|
|
|||
|
|
Adrien Devresse,
|
|||
|
|
Alexander Ried,
|
|||
|
|
Alex Cruice,
|
|||
|
|
Alexey Shmalko,
|
|||
|
|
AmineChikhaoui,
|
|||
|
|
Andy Wingo,
|
|||
|
|
Aneesh Agrawal,
|
|||
|
|
Anthony Cowley,
|
|||
|
|
Armijn Hemel,
|
|||
|
|
aszlig,
|
|||
|
|
Ben Gamari,
|
|||
|
|
Benjamin Hipple,
|
|||
|
|
Benjamin Staffin,
|
|||
|
|
Benno Fünfstück,
|
|||
|
|
Bjørn Forsman,
|
|||
|
|
Brian McKenna,
|
|||
|
|
Charles Strahan,
|
|||
|
|
Chase Adams,
|
|||
|
|
Chris Martin,
|
|||
|
|
Christian Theune,
|
|||
|
|
Chris Warburton,
|
|||
|
|
Daiderd Jordan,
|
|||
|
|
Dan Connolly,
|
|||
|
|
Daniel Peebles,
|
|||
|
|
Dan Peebles,
|
|||
|
|
davidak,
|
|||
|
|
David McFarland,
|
|||
|
|
Dmitry Kalinkin,
|
|||
|
|
Domen Kožar,
|
|||
|
|
Eelco Dolstra,
|
|||
|
|
Emery Hemingway,
|
|||
|
|
Eric Litak,
|
|||
|
|
Eric Wolf,
|
|||
|
|
Fabian Schmitthenner,
|
|||
|
|
Frederik Rietdijk,
|
|||
|
|
Gabriel Gonzalez,
|
|||
|
|
Giorgio Gallo,
|
|||
|
|
Graham Christensen,
|
|||
|
|
Guillaume Maudoux,
|
|||
|
|
Harmen,
|
|||
|
|
Iavael,
|
|||
|
|
James Broadhead,
|
|||
|
|
James Earl Douglas,
|
|||
|
|
Janus Troelsen,
|
|||
|
|
Jeremy Shaw,
|
|||
|
|
Joachim Schiele,
|
|||
|
|
Joe Hermaszewski,
|
|||
|
|
Joel Moberg,
|
|||
|
|
Johannes 'fish' Ziemke,
|
|||
|
|
Jörg Thalheim,
|
|||
|
|
Jude Taylor,
|
|||
|
|
kballou,
|
|||
|
|
Keshav Kini,
|
|||
|
|
Kjetil Orbekk,
|
|||
|
|
Langston Barrett,
|
|||
|
|
Linus Heckemann,
|
|||
|
|
Ludovic Courtès,
|
|||
|
|
Manav Rathi,
|
|||
|
|
Marc Scholten,
|
|||
|
|
Markus Hauck,
|
|||
|
|
Matt Audesse,
|
|||
|
|
Matthew Bauer,
|
|||
|
|
Matthias Beyer,
|
|||
|
|
Matthieu Coudron,
|
|||
|
|
N1X,
|
|||
|
|
Nathan Zadoks,
|
|||
|
|
Neil Mayhew,
|
|||
|
|
Nicolas B. Pierron,
|
|||
|
|
Niklas Hambüchen,
|
|||
|
|
Nikolay Amiantov,
|
|||
|
|
Ole Jørgen Brønner,
|
|||
|
|
Orivej Desh,
|
|||
|
|
Peter Simons,
|
|||
|
|
Peter Stuart,
|
|||
|
|
Pyry Jahkola,
|
|||
|
|
regnat,
|
|||
|
|
Renzo Carbonara,
|
|||
|
|
Rhys,
|
|||
|
|
Robert Vollmert,
|
|||
|
|
Scott Olson,
|
|||
|
|
Scott R. Parish,
|
|||
|
|
Sergei Trofimovich,
|
|||
|
|
Shea Levy,
|
|||
|
|
Sheena Artrip,
|
|||
|
|
Spencer Baugh,
|
|||
|
|
Stefan Junker,
|
|||
|
|
Susan Potter,
|
|||
|
|
Thomas Tuegel,
|
|||
|
|
Timothy Allen,
|
|||
|
|
Tristan Hume,
|
|||
|
|
Tuomas Tynkkynen,
|
|||
|
|
tv,
|
|||
|
|
Tyson Whitehead,
|
|||
|
|
Vladimír Čunát,
|
|||
|
|
Will Dietz,
|
|||
|
|
wmertens,
|
|||
|
|
Wout Mertens,
|
|||
|
|
zimbatm and
|
|||
|
|
Zoran Plesivčak.
|
|||
|
|
</p></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a id="ssec-relnotes-1.11.10"></a>C.5. Release 1.11.10 (2017-06-12)</h2></div></div></div><p>This release fixes a security bug in Nix’s “build user” build
|
|||
|
|
isolation mechanism. Previously, Nix builders had the ability to
|
|||
|
|
create setuid binaries owned by a <code class="literal">nixbld</code>
|
|||
|
|
user. Such a binary could then be used by an attacker to assume a
|
|||
|
|
<code class="literal">nixbld</code> identity and interfere with subsequent
|
|||
|
|
builds running under the same UID.</p><p>To prevent this issue, Nix now disallows builders to create
|
|||
|
|
setuid and setgid binaries. On Linux, this is done using a seccomp BPF
|
|||
|
|
filter. Note that this imposes a small performance penalty (e.g. 1%
|
|||
|
|
when building GNU Hello). Using seccomp, we now also prevent the
|
|||
|
|
creation of extended attributes and POSIX ACLs since these cannot be
|
|||
|
|
represented in the NAR format and (in the case of POSIX ACLs) allow
|
|||
|
|
bypassing regular Nix store permissions. On macOS, the restriction is
|
|||
|
|
implemented using the existing sandbox mechanism, which now uses a
|
|||
|
|
minimal “allow all except the creation of setuid/setgid binaries”
|
|||
|
|
profile when regular sandboxing is disabled. On other platforms, the
|
|||
|
|
“build user” mechanism is now disabled.</p><p>Thanks go to Linus Heckemann for discovering and reporting this
|
|||
|
|
bug.</p></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a id="ssec-relnotes-1.11"></a>C.6. Release 1.11 (2016-01-19)</h2></div></div></div><p>This is primarily a bug fix release. It also has a number of new
|
|||
|
|
features:</p><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><p><span class="command"><strong>nix-prefetch-url</strong></span> can now download URLs
|
|||
|
|
specified in a Nix expression. For example,
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-prefetch-url -A hello.src
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
will prefetch the file specified by the
|
|||
|
|
<code class="function">fetchurl</code> call in the attribute
|
|||
|
|
<code class="literal">hello.src</code> from the Nix expression in the
|
|||
|
|
current directory, and print the cryptographic hash of the
|
|||
|
|
resulting file on stdout. This differs from <code class="literal">nix-build -A
|
|||
|
|
hello.src</code> in that it doesn't verify the hash, and is
|
|||
|
|
thus useful when you’re updating a Nix expression.</p><p>You can also prefetch the result of functions that unpack a
|
|||
|
|
tarball, such as <code class="function">fetchFromGitHub</code>. For example:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-prefetch-url --unpack https://github.com/NixOS/patchelf/archive/0.8.tar.gz
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
or from a Nix expression:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-prefetch-url -A nix-repl.src
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
</p></li><li class="listitem"><p>The builtin function
|
|||
|
|
<code class="function"><nix/fetchurl.nix></code> now supports
|
|||
|
|
downloading and unpacking NARs. This removes the need to have
|
|||
|
|
multiple downloads in the Nixpkgs stdenv bootstrap process (like a
|
|||
|
|
separate busybox binary for Linux, or curl/mkdir/sh/bzip2 for
|
|||
|
|
Darwin). Now all those files can be combined into a single NAR,
|
|||
|
|
optionally compressed using <span class="command"><strong>xz</strong></span>.</p></li><li class="listitem"><p>Nix now supports SHA-512 hashes for verifying fixed-output
|
|||
|
|
derivations, and in <code class="function">builtins.hashString</code>.</p></li><li class="listitem"><p>
|
|||
|
|
The new flag <code class="option">--option build-repeat
|
|||
|
|
<em class="replaceable"><code>N</code></em></code> will cause every build to
|
|||
|
|
be executed <em class="replaceable"><code>N</code></em>+1 times. If the build
|
|||
|
|
output differs between any round, the build is rejected, and the
|
|||
|
|
output paths are not registered as valid. This is primarily
|
|||
|
|
useful to verify build determinism. (We already had a
|
|||
|
|
<code class="option">--check</code> option to repeat a previously succeeded
|
|||
|
|
build. However, with <code class="option">--check</code>, non-deterministic
|
|||
|
|
builds are registered in the DB. Preventing that is useful for
|
|||
|
|
Hydra to ensure that non-deterministic builds don't end up
|
|||
|
|
getting published to the binary cache.)
|
|||
|
|
</p></li><li class="listitem"><p>
|
|||
|
|
The options <code class="option">--check</code> and <code class="option">--option
|
|||
|
|
build-repeat <em class="replaceable"><code>N</code></em></code>, if they
|
|||
|
|
detect a difference between two runs of the same derivation and
|
|||
|
|
<code class="option">-K</code> is given, will make the output of the other
|
|||
|
|
run available under
|
|||
|
|
<code class="filename"><em class="replaceable"><code>store-path</code></em>-check</code>. This
|
|||
|
|
makes it easier to investigate the non-determinism using tools
|
|||
|
|
like <span class="command"><strong>diffoscope</strong></span>, e.g.,
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-build pkgs/stdenv/linux -A stage1.pkgs.zlib --check -K
|
|||
|
|
error: derivation ‘/nix/store/l54i8wlw2265…-zlib-1.2.8.drv’ may not
|
|||
|
|
be deterministic: output ‘/nix/store/11a27shh6n2i…-zlib-1.2.8’
|
|||
|
|
differs from ‘/nix/store/11a27shh6n2i…-zlib-1.2.8-check’
|
|||
|
|
|
|||
|
|
$ diffoscope /nix/store/11a27shh6n2i…-zlib-1.2.8 /nix/store/11a27shh6n2i…-zlib-1.2.8-check
|
|||
|
|
…
|
|||
|
|
├── lib/libz.a
|
|||
|
|
│ ├── metadata
|
|||
|
|
│ │ @@ -1,15 +1,15 @@
|
|||
|
|
│ │ -rw-r--r-- 30001/30000 3096 Jan 12 15:20 2016 adler32.o
|
|||
|
|
…
|
|||
|
|
│ │ +rw-r--r-- 30001/30000 3096 Jan 12 15:28 2016 adler32.o
|
|||
|
|
…
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
</p></li><li class="listitem"><p>Improved FreeBSD support.</p></li><li class="listitem"><p><span class="command"><strong>nix-env -qa --xml --meta</strong></span> now prints
|
|||
|
|
license information.</p></li><li class="listitem"><p>The maximum number of parallel TCP connections that the
|
|||
|
|
binary cache substituter will use has been decreased from 150 to
|
|||
|
|
25. This should prevent upsetting some broken NAT routers, and
|
|||
|
|
also improves performance.</p></li><li class="listitem"><p>All "chroot"-containing strings got renamed to "sandbox".
|
|||
|
|
In particular, some Nix options got renamed, but the old names
|
|||
|
|
are still accepted as lower-priority aliases.
|
|||
|
|
</p></li></ul></div><p>This release has contributions from Anders Claesson, Anthony
|
|||
|
|
Cowley, Bjørn Forsman, Brian McKenna, Danny Wilson, davidak, Eelco Dolstra,
|
|||
|
|
Fabian Schmitthenner, FrankHB, Ilya Novoselov, janus, Jim Garrison, John
|
|||
|
|
Ericson, Jude Taylor, Ludovic Courtès, Manuel Jacob, Mathnerd314,
|
|||
|
|
Pascal Wittmann, Peter Simons, Philip Potter, Preston Bennes, Rommel
|
|||
|
|
M. Martinez, Sander van der Burg, Shea Levy, Tim Cuthbertson, Tuomas
|
|||
|
|
Tynkkynen, Utku Demir and Vladimír Čunát.</p></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a id="ssec-relnotes-1.10"></a>C.7. Release 1.10 (2015-09-03)</h2></div></div></div><p>This is primarily a bug fix release. It also has a number of new
|
|||
|
|
features:</p><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><p>A number of builtin functions have been added to reduce
|
|||
|
|
Nixpkgs/NixOS evaluation time and memory consumption:
|
|||
|
|
<code class="function">all</code>,
|
|||
|
|
<code class="function">any</code>,
|
|||
|
|
<code class="function">concatStringsSep</code>,
|
|||
|
|
<code class="function">foldl’</code>,
|
|||
|
|
<code class="function">genList</code>,
|
|||
|
|
<code class="function">replaceStrings</code>,
|
|||
|
|
<code class="function">sort</code>.
|
|||
|
|
</p></li><li class="listitem"><p>The garbage collector is more robust when the disk is full.</p></li><li class="listitem"><p>Nix supports a new API for building derivations that doesn’t
|
|||
|
|
require a <code class="literal">.drv</code> file to be present on disk; it
|
|||
|
|
only requires an in-memory representation of the derivation. This
|
|||
|
|
is used by the Hydra continuous build system to make remote builds
|
|||
|
|
more efficient.</p></li><li class="listitem"><p>The function <code class="literal"><nix/fetchurl.nix></code> now
|
|||
|
|
uses a <span class="emphasis"><em>builtin</em></span> builder (i.e. it doesn’t
|
|||
|
|
require starting an external process; the download is performed by
|
|||
|
|
Nix itself). This ensures that derivation paths don’t change when
|
|||
|
|
Nix is upgraded, and obviates the need for ugly hacks to support
|
|||
|
|
chroot execution.</p></li><li class="listitem"><p><code class="option">--version -v</code> now prints some configuration
|
|||
|
|
information, in particular what compile-time optional features are
|
|||
|
|
enabled, and the paths of various directories.</p></li><li class="listitem"><p>Build users have their supplementary groups set correctly.</p></li></ul></div><p>This release has contributions from Eelco Dolstra, Guillaume
|
|||
|
|
Maudoux, Iwan Aucamp, Jaka Hudoklin, Kirill Elagin, Ludovic Courtès,
|
|||
|
|
Manolis Ragkousis, Nicolas B. Pierron and Shea Levy.</p></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a id="ssec-relnotes-1.9"></a>C.8. Release 1.9 (2015-06-12)</h2></div></div></div><p>In addition to the usual bug fixes, this release has the
|
|||
|
|
following new features:</p><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><p>Signed binary cache support. You can enable signature
|
|||
|
|
checking by adding the following to <code class="filename">nix.conf</code>:
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
signed-binary-caches = *
|
|||
|
|
binary-cache-public-keys = cache.nixos.org-1:6NCHdD59X431o0gWypbMrAURkbJ16ZPMQFGspcDShjY=
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
This will prevent Nix from downloading any binary from the cache
|
|||
|
|
that is not signed by one of the keys listed in
|
|||
|
|
<code class="option">binary-cache-public-keys</code>.</p><p>Signature checking is only supported if you built Nix with
|
|||
|
|
the <code class="literal">libsodium</code> package.</p><p>Note that while Nix has had experimental support for signed
|
|||
|
|
binary caches since version 1.7, this release changes the
|
|||
|
|
signature format in a backwards-incompatible way.</p></li><li class="listitem"><p>Automatic downloading of Nix expression tarballs. In various
|
|||
|
|
places, you can now specify the URL of a tarball containing Nix
|
|||
|
|
expressions (such as Nixpkgs), which will be downloaded and
|
|||
|
|
unpacked automatically. For example:</p><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: circle; "><li class="listitem"><p>In <span class="command"><strong>nix-env</strong></span>:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-env -f https://github.com/NixOS/nixpkgs-channels/archive/nixos-14.12.tar.gz -iA firefox
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
This installs Firefox from the latest tested and built revision
|
|||
|
|
of the NixOS 14.12 channel.</p></li><li class="listitem"><p>In <span class="command"><strong>nix-build</strong></span> and
|
|||
|
|
<span class="command"><strong>nix-shell</strong></span>:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-build https://github.com/NixOS/nixpkgs/archive/master.tar.gz -A hello
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
This builds GNU Hello from the latest revision of the Nixpkgs
|
|||
|
|
master branch.</p></li><li class="listitem"><p>In the Nix search path (as specified via
|
|||
|
|
<code class="envar">NIX_PATH</code> or <code class="option">-I</code>). For example, to
|
|||
|
|
start a shell containing the Pan package from a specific version
|
|||
|
|
of Nixpkgs:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-shell -p pan -I nixpkgs=https://github.com/NixOS/nixpkgs-channels/archive/8a3eea054838b55aca962c3fbde9c83c102b8bf2.tar.gz
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
</p></li><li class="listitem"><p>In <span class="command"><strong>nixos-rebuild</strong></span> (on NixOS):
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nixos-rebuild test -I nixpkgs=https://github.com/NixOS/nixpkgs-channels/archive/nixos-unstable.tar.gz
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
</p></li><li class="listitem"><p>In Nix expressions, via the new builtin function <code class="function">fetchTarball</code>:
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
with import (fetchTarball https://github.com/NixOS/nixpkgs-channels/archive/nixos-14.12.tar.gz) {}; …
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
(This is not allowed in restricted mode.)</p></li></ul></div></li><li class="listitem"><p><span class="command"><strong>nix-shell</strong></span> improvements:</p><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: circle; "><li class="listitem"><p><span class="command"><strong>nix-shell</strong></span> now has a flag
|
|||
|
|
<code class="option">--run</code> to execute a command in the
|
|||
|
|
<span class="command"><strong>nix-shell</strong></span> environment,
|
|||
|
|
e.g. <code class="literal">nix-shell --run make</code>. This is like
|
|||
|
|
the existing <code class="option">--command</code> flag, except that it
|
|||
|
|
uses a non-interactive shell (ensuring that hitting Ctrl-C won’t
|
|||
|
|
drop you into the child shell).</p></li><li class="listitem"><p><span class="command"><strong>nix-shell</strong></span> can now be used as
|
|||
|
|
a <code class="literal">#!</code>-interpreter. This allows you to write
|
|||
|
|
scripts that dynamically fetch their own dependencies. For
|
|||
|
|
example, here is a Haskell script that, when invoked, first
|
|||
|
|
downloads GHC and the Haskell packages on which it depends:
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
#! /usr/bin/env nix-shell
|
|||
|
|
#! nix-shell -i runghc -p haskellPackages.ghc haskellPackages.HTTP
|
|||
|
|
|
|||
|
|
import Network.HTTP
|
|||
|
|
|
|||
|
|
main = do
|
|||
|
|
resp <- Network.HTTP.simpleHTTP (getRequest "http://nixos.org/")
|
|||
|
|
body <- getResponseBody resp
|
|||
|
|
print (take 100 body)
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
Of course, the dependencies are cached in the Nix store, so the
|
|||
|
|
second invocation of this script will be much
|
|||
|
|
faster.</p></li></ul></div></li><li class="listitem"><p>Chroot improvements:</p><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: circle; "><li class="listitem"><p>Chroot builds are now supported on Mac OS X
|
|||
|
|
(using its sandbox mechanism).</p></li><li class="listitem"><p>If chroots are enabled, they are now used for
|
|||
|
|
all derivations, including fixed-output derivations (such as
|
|||
|
|
<code class="function">fetchurl</code>). The latter do have network
|
|||
|
|
access, but can no longer access the host filesystem. If you
|
|||
|
|
need the old behaviour, you can set the option
|
|||
|
|
<code class="option">build-use-chroot</code> to
|
|||
|
|
<code class="literal">relaxed</code>.</p></li><li class="listitem"><p>On Linux, if chroots are enabled, builds are
|
|||
|
|
performed in a private PID namespace once again. (This
|
|||
|
|
functionality was lost in Nix 1.8.)</p></li><li class="listitem"><p>Store paths listed in
|
|||
|
|
<code class="option">build-chroot-dirs</code> are now automatically
|
|||
|
|
expanded to their closure. For instance, if you want
|
|||
|
|
<code class="filename">/nix/store/…-bash/bin/sh</code> mounted in your
|
|||
|
|
chroot as <code class="filename">/bin/sh</code>, you only need to say
|
|||
|
|
<code class="literal">build-chroot-dirs =
|
|||
|
|
/bin/sh=/nix/store/…-bash/bin/sh</code>; it is no longer
|
|||
|
|
necessary to specify the dependencies of Bash.</p></li></ul></div></li><li class="listitem"><p>The new derivation attribute
|
|||
|
|
<code class="varname">passAsFile</code> allows you to specify that the
|
|||
|
|
contents of derivation attributes should be passed via files rather
|
|||
|
|
than environment variables. This is useful if you need to pass very
|
|||
|
|
long strings that exceed the size limit of the environment. The
|
|||
|
|
Nixpkgs function <code class="function">writeTextFile</code> uses
|
|||
|
|
this.</p></li><li class="listitem"><p>You can now use <code class="literal">~</code> in Nix file
|
|||
|
|
names to refer to your home directory, e.g. <code class="literal">import
|
|||
|
|
~/.nixpkgs/config.nix</code>.</p></li><li class="listitem"><p>Nix has a new option <code class="option">restrict-eval</code>
|
|||
|
|
that allows limiting what paths the Nix evaluator has access to. By
|
|||
|
|
passing <code class="literal">--option restrict-eval true</code> to Nix, the
|
|||
|
|
evaluator will throw an exception if an attempt is made to access
|
|||
|
|
any file outside of the Nix search path. This is primarily intended
|
|||
|
|
for Hydra to ensure that a Hydra jobset only refers to its declared
|
|||
|
|
inputs (and is therefore reproducible).</p></li><li class="listitem"><p><span class="command"><strong>nix-env</strong></span> now only creates a new
|
|||
|
|
“generation” symlink in <code class="filename">/nix/var/nix/profiles</code>
|
|||
|
|
if something actually changed.</p></li><li class="listitem"><p>The environment variable <code class="envar">NIX_PAGER</code>
|
|||
|
|
can now be set to override <code class="envar">PAGER</code>. You can set it to
|
|||
|
|
<code class="literal">cat</code> to disable paging for Nix commands
|
|||
|
|
only.</p></li><li class="listitem"><p>Failing <code class="literal"><...></code>
|
|||
|
|
lookups now show position information.</p></li><li class="listitem"><p>Improved Boehm GC use: we disabled scanning for
|
|||
|
|
interior pointers, which should reduce the “<code class="literal">Repeated
|
|||
|
|
allocation of very large block</code>” warnings and associated
|
|||
|
|
retention of memory.</p></li></ul></div><p>This release has contributions from aszlig, Benjamin Staffin,
|
|||
|
|
Charles Strahan, Christian Theune, Daniel Hahler, Danylo Hlynskyi
|
|||
|
|
Daniel Peebles, Dan Peebles, Domen Kožar, Eelco Dolstra, Harald van
|
|||
|
|
Dijk, Hoang Xuan Phu, Jaka Hudoklin, Jeff Ramnani, j-keck, Linquize,
|
|||
|
|
Luca Bruno, Michael Merickel, Oliver Dunkl, Rob Vermaas, Rok Garbas,
|
|||
|
|
Shea Levy, Tobias Geerinckx-Rice and William A. Kennington III.</p></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a id="ssec-relnotes-1.8"></a>C.9. Release 1.8 (2014-12-14)</h2></div></div></div><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><p>Breaking change: to address a race condition, the
|
|||
|
|
remote build hook mechanism now uses <span class="command"><strong>nix-store
|
|||
|
|
--serve</strong></span> on the remote machine. This requires build slaves
|
|||
|
|
to be updated to Nix 1.8.</p></li><li class="listitem"><p>Nix now uses HTTPS instead of HTTP to access the
|
|||
|
|
default binary cache,
|
|||
|
|
<code class="literal">cache.nixos.org</code>.</p></li><li class="listitem"><p><span class="command"><strong>nix-env</strong></span> selectors are now regular
|
|||
|
|
expressions. For instance, you can do
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-env -qa '.*zip.*'
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
to query all packages with a name containing
|
|||
|
|
<code class="literal">zip</code>.</p></li><li class="listitem"><p><span class="command"><strong>nix-store --read-log</strong></span> can now
|
|||
|
|
fetch remote build logs. If a build log is not available locally,
|
|||
|
|
then ‘nix-store -l’ will now try to download it from the servers
|
|||
|
|
listed in the ‘log-servers’ option in nix.conf. For instance, if you
|
|||
|
|
have the configuration option
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
log-servers = http://hydra.nixos.org/log
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
then it will try to get logs from
|
|||
|
|
<code class="literal">http://hydra.nixos.org/log/<em class="replaceable"><code>base name of the
|
|||
|
|
store path</code></em></code>. This allows you to do things like:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-store -l $(which xterm)
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
and get a log even if <span class="command"><strong>xterm</strong></span> wasn't built
|
|||
|
|
locally.</p></li><li class="listitem"><p>New builtin functions:
|
|||
|
|
<code class="function">attrValues</code>, <code class="function">deepSeq</code>,
|
|||
|
|
<code class="function">fromJSON</code>, <code class="function">readDir</code>,
|
|||
|
|
<code class="function">seq</code>.</p></li><li class="listitem"><p><span class="command"><strong>nix-instantiate --eval</strong></span> now has a
|
|||
|
|
<code class="option">--json</code> flag to print the resulting value in JSON
|
|||
|
|
format.</p></li><li class="listitem"><p><span class="command"><strong>nix-copy-closure</strong></span> now uses
|
|||
|
|
<span class="command"><strong>nix-store --serve</strong></span> on the remote side to send or
|
|||
|
|
receive closures. This fixes a race condition between
|
|||
|
|
<span class="command"><strong>nix-copy-closure</strong></span> and the garbage
|
|||
|
|
collector.</p></li><li class="listitem"><p>Derivations can specify the new special attribute
|
|||
|
|
<code class="varname">allowedRequisites</code>, which has a similar meaning to
|
|||
|
|
<code class="varname">allowedReferences</code>. But instead of only enforcing
|
|||
|
|
to explicitly specify the immediate references, it requires the
|
|||
|
|
derivation to specify all the dependencies recursively (hence the
|
|||
|
|
name, requisites) that are used by the resulting
|
|||
|
|
output.</p></li><li class="listitem"><p>On Mac OS X, Nix now handles case collisions when
|
|||
|
|
importing closures from case-sensitive file systems. This is mostly
|
|||
|
|
useful for running NixOps on Mac OS X.</p></li><li class="listitem"><p>The Nix daemon has new configuration options
|
|||
|
|
<code class="option">allowed-users</code> (specifying the users and groups that
|
|||
|
|
are allowed to connect to the daemon) and
|
|||
|
|
<code class="option">trusted-users</code> (specifying the users and groups that
|
|||
|
|
can perform privileged operations like specifying untrusted binary
|
|||
|
|
caches).</p></li><li class="listitem"><p>The configuration option
|
|||
|
|
<code class="option">build-cores</code> now defaults to the number of available
|
|||
|
|
CPU cores.</p></li><li class="listitem"><p>Build users are now used by default when Nix is
|
|||
|
|
invoked as root. This prevents builds from accidentally running as
|
|||
|
|
root.</p></li><li class="listitem"><p>Nix now includes systemd units and Upstart
|
|||
|
|
jobs.</p></li><li class="listitem"><p>Speed improvements to <span class="command"><strong>nix-store
|
|||
|
|
--optimise</strong></span>.</p></li><li class="listitem"><p>Language change: the <code class="literal">==</code> operator
|
|||
|
|
now ignores string contexts (the “dependencies” of a
|
|||
|
|
string).</p></li><li class="listitem"><p>Nix now filters out Nix-specific ANSI escape
|
|||
|
|
sequences on standard error. They are supposed to be invisible, but
|
|||
|
|
some terminals show them anyway.</p></li><li class="listitem"><p>Various commands now automatically pipe their output
|
|||
|
|
into the pager as specified by the <code class="envar">PAGER</code> environment
|
|||
|
|
variable.</p></li><li class="listitem"><p>Several improvements to reduce memory consumption in
|
|||
|
|
the evaluator.</p></li></ul></div><p>This release has contributions from Adam Szkoda, Aristid
|
|||
|
|
Breitkreuz, Bob van der Linden, Charles Strahan, darealshinji, Eelco
|
|||
|
|
Dolstra, Gergely Risko, Joel Taylor, Ludovic Courtès, Marko Durkovic,
|
|||
|
|
Mikey Ariel, Paul Colomiets, Ricardo M. Correia, Ricky Elrod, Robert
|
|||
|
|
Helgesson, Rob Vermaas, Russell O'Connor, Shea Levy, Shell Turner,
|
|||
|
|
Sönke Hahn, Steve Purcell, Vladimír Čunát and Wout Mertens.</p></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a id="ssec-relnotes-1.7"></a>C.10. Release 1.7 (2014-04-11)</h2></div></div></div><p>In addition to the usual bug fixes, this release has the
|
|||
|
|
following new features:</p><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><p>Antiquotation is now allowed inside of quoted attribute
|
|||
|
|
names (e.g. <code class="literal">set."${foo}"</code>). In the case where
|
|||
|
|
the attribute name is just a single antiquotation, the quotes can
|
|||
|
|
be dropped (e.g. the above example can be written
|
|||
|
|
<code class="literal">set.${foo}</code>). If an attribute name inside of a
|
|||
|
|
set declaration evaluates to <code class="literal">null</code> (e.g.
|
|||
|
|
<code class="literal">{ ${null} = false; }</code>), then that attribute is
|
|||
|
|
not added to the set.</p></li><li class="listitem"><p>Experimental support for cryptographically signed binary
|
|||
|
|
caches. See <a class="link" href="https://github.com/NixOS/nix/commit/0fdf4da0e979f992db75cc17376e455ddc5a96d8" target="_top">the
|
|||
|
|
commit for details</a>.</p></li><li class="listitem"><p>An experimental new substituter,
|
|||
|
|
<span class="command"><strong>download-via-ssh</strong></span>, that fetches binaries from
|
|||
|
|
remote machines via SSH. Specifying the flags <code class="literal">--option
|
|||
|
|
use-ssh-substituter true --option ssh-substituter-hosts
|
|||
|
|
<em class="replaceable"><code>user@hostname</code></em></code> will cause Nix
|
|||
|
|
to download binaries from the specified machine, if it has
|
|||
|
|
them.</p></li><li class="listitem"><p><span class="command"><strong>nix-store -r</strong></span> and
|
|||
|
|
<span class="command"><strong>nix-build</strong></span> have a new flag,
|
|||
|
|
<code class="option">--check</code>, that builds a previously built
|
|||
|
|
derivation again, and prints an error message if the output is not
|
|||
|
|
exactly the same. This helps to verify whether a derivation is
|
|||
|
|
truly deterministic. For example:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-build '<nixpkgs>' -A patchelf
|
|||
|
|
<em class="replaceable"><code>…</code></em>
|
|||
|
|
$ nix-build '<nixpkgs>' -A patchelf --check
|
|||
|
|
<em class="replaceable"><code>…</code></em>
|
|||
|
|
error: derivation `/nix/store/1ipvxs…-patchelf-0.6' may not be deterministic:
|
|||
|
|
hash mismatch in output `/nix/store/4pc1dm…-patchelf-0.6.drv'
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
</p></li><li class="listitem"><p>The <span class="command"><strong>nix-instantiate</strong></span> flags
|
|||
|
|
<code class="option">--eval-only</code> and <code class="option">--parse-only</code>
|
|||
|
|
have been renamed to <code class="option">--eval</code> and
|
|||
|
|
<code class="option">--parse</code>, respectively.</p></li><li class="listitem"><p><span class="command"><strong>nix-instantiate</strong></span>,
|
|||
|
|
<span class="command"><strong>nix-build</strong></span> and <span class="command"><strong>nix-shell</strong></span> now
|
|||
|
|
have a flag <code class="option">--expr</code> (or <code class="option">-E</code>) that
|
|||
|
|
allows you to specify the expression to be evaluated as a command
|
|||
|
|
line argument. For instance, <code class="literal">nix-instantiate --eval -E
|
|||
|
|
'1 + 2'</code> will print <code class="literal">3</code>.</p></li><li class="listitem"><p><span class="command"><strong>nix-shell</strong></span> improvements:</p><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: circle; "><li class="listitem"><p>It has a new flag, <code class="option">--packages</code> (or
|
|||
|
|
<code class="option">-p</code>), that sets up a build environment
|
|||
|
|
containing the specified packages from Nixpkgs. For example,
|
|||
|
|
the command
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-shell -p sqlite xorg.libX11 hello
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
will start a shell in which the given packages are
|
|||
|
|
present.</p></li><li class="listitem"><p>It now uses <code class="filename">shell.nix</code> as the
|
|||
|
|
default expression, falling back to
|
|||
|
|
<code class="filename">default.nix</code> if the former doesn’t
|
|||
|
|
exist. This makes it convenient to have a
|
|||
|
|
<code class="filename">shell.nix</code> in your project to set up a
|
|||
|
|
nice development environment.</p></li><li class="listitem"><p>It evaluates the derivation attribute
|
|||
|
|
<code class="varname">shellHook</code>, if set. Since
|
|||
|
|
<code class="literal">stdenv</code> does not normally execute this hook,
|
|||
|
|
it allows you to do <span class="command"><strong>nix-shell</strong></span>-specific
|
|||
|
|
setup.</p></li><li class="listitem"><p>It preserves the user’s timezone setting.</p></li></ul></div></li><li class="listitem"><p>In chroots, Nix now sets up a <code class="filename">/dev</code>
|
|||
|
|
containing only a minimal set of devices (such as
|
|||
|
|
<code class="filename">/dev/null</code>). Note that it only does this if
|
|||
|
|
you <span class="emphasis"><em>don’t</em></span> have <code class="filename">/dev</code>
|
|||
|
|
listed in your <code class="option">build-chroot-dirs</code> setting;
|
|||
|
|
otherwise, it will bind-mount the <code class="literal">/dev</code> from
|
|||
|
|
outside the chroot.</p><p>Similarly, if you don’t have <code class="filename">/dev/pts</code> listed
|
|||
|
|
in <code class="option">build-chroot-dirs</code>, Nix will mount a private
|
|||
|
|
<code class="literal">devpts</code> filesystem on the chroot’s
|
|||
|
|
<code class="filename">/dev/pts</code>.</p></li><li class="listitem"><p>New built-in function: <code class="function">builtins.toJSON</code>,
|
|||
|
|
which returns a JSON representation of a value.</p></li><li class="listitem"><p><span class="command"><strong>nix-env -q</strong></span> has a new flag
|
|||
|
|
<code class="option">--json</code> to print a JSON representation of the
|
|||
|
|
installed or available packages.</p></li><li class="listitem"><p><span class="command"><strong>nix-env</strong></span> now supports meta attributes with
|
|||
|
|
more complex values, such as attribute sets.</p></li><li class="listitem"><p>The <code class="option">-A</code> flag now allows attribute names with
|
|||
|
|
dots in them, e.g.
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-instantiate --eval '<nixos>' -A 'config.systemd.units."nscd.service".text'
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
</p></li><li class="listitem"><p>The <code class="option">--max-freed</code> option to
|
|||
|
|
<span class="command"><strong>nix-store --gc</strong></span> now accepts a unit
|
|||
|
|
specifier. For example, <code class="literal">nix-store --gc --max-freed
|
|||
|
|
1G</code> will free up to 1 gigabyte of disk space.</p></li><li class="listitem"><p><span class="command"><strong>nix-collect-garbage</strong></span> has a new flag
|
|||
|
|
<code class="option">--delete-older-than</code>
|
|||
|
|
<em class="replaceable"><code>N</code></em><code class="literal">d</code>, which deletes
|
|||
|
|
all user environment generations older than
|
|||
|
|
<em class="replaceable"><code>N</code></em> days. Likewise, <span class="command"><strong>nix-env
|
|||
|
|
--delete-generations</strong></span> accepts a
|
|||
|
|
<em class="replaceable"><code>N</code></em><code class="literal">d</code> age limit.</p></li><li class="listitem"><p>Nix now heuristically detects whether a build failure was
|
|||
|
|
due to a disk-full condition. In that case, the build is not
|
|||
|
|
flagged as “permanently failed”. This is mostly useful for Hydra,
|
|||
|
|
which needs to distinguish between permanent and transient build
|
|||
|
|
failures.</p></li><li class="listitem"><p>There is a new symbol <code class="literal">__curPos</code> that
|
|||
|
|
expands to an attribute set containing its file name and line and
|
|||
|
|
column numbers, e.g. <code class="literal">{ file = "foo.nix"; line = 10;
|
|||
|
|
column = 5; }</code>. There also is a new builtin function,
|
|||
|
|
<code class="varname">unsafeGetAttrPos</code>, that returns the position of
|
|||
|
|
an attribute. This is used by Nixpkgs to provide location
|
|||
|
|
information in error messages, e.g.
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-build '<nixpkgs>' -A libreoffice --argstr system x86_64-darwin
|
|||
|
|
error: the package ‘libreoffice-4.0.5.2’ in ‘.../applications/office/libreoffice/default.nix:263’
|
|||
|
|
is not supported on ‘x86_64-darwin’
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
</p></li><li class="listitem"><p>The garbage collector is now more concurrent with other Nix
|
|||
|
|
processes because it releases certain locks earlier.</p></li><li class="listitem"><p>The binary tarball installer has been improved. You can now
|
|||
|
|
install Nix by running:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ bash <(curl https://nixos.org/nix/install)
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
</p></li><li class="listitem"><p>More evaluation errors include position information. For
|
|||
|
|
instance, selecting a missing attribute will print something like
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
error: attribute `nixUnstabl' missing, at /etc/nixos/configurations/misc/eelco/mandark.nix:216:15
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
</p></li><li class="listitem"><p>The command <span class="command"><strong>nix-setuid-helper</strong></span> is
|
|||
|
|
gone.</p></li><li class="listitem"><p>Nix no longer uses Automake, but instead has a
|
|||
|
|
non-recursive, GNU Make-based build system.</p></li><li class="listitem"><p>All installed libraries now have the prefix
|
|||
|
|
<code class="literal">libnix</code>. In particular, this gets rid of
|
|||
|
|
<code class="literal">libutil</code>, which could clash with libraries with
|
|||
|
|
the same name from other packages.</p></li><li class="listitem"><p>Nix now requires a compiler that supports C++11.</p></li></ul></div><p>This release has contributions from Danny Wilson, Domen Kožar,
|
|||
|
|
Eelco Dolstra, Ian-Woo Kim, Ludovic Courtès, Maxim Ivanov, Petr
|
|||
|
|
Rockai, Ricardo M. Correia and Shea Levy.</p></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a id="ssec-relnotes-1.6.1"></a>C.11. Release 1.6.1 (2013-10-28)</h2></div></div></div><p>This is primarily a bug fix release. Changes of interest
|
|||
|
|
are:</p><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><p>Nix 1.6 accidentally changed the semantics of antiquoted
|
|||
|
|
paths in strings, such as <code class="literal">"${/foo}/bar"</code>. This
|
|||
|
|
release reverts to the Nix 1.5.3 behaviour.</p></li><li class="listitem"><p>Previously, Nix optimised expressions such as
|
|||
|
|
<code class="literal">"${<em class="replaceable"><code>expr</code></em>}"</code> to
|
|||
|
|
<em class="replaceable"><code>expr</code></em>. Thus it neither checked whether
|
|||
|
|
<em class="replaceable"><code>expr</code></em> could be coerced to a string, nor
|
|||
|
|
applied such coercions. This meant that
|
|||
|
|
<code class="literal">"${123}"</code> evaluatued to <code class="literal">123</code>,
|
|||
|
|
and <code class="literal">"${./foo}"</code> evaluated to
|
|||
|
|
<code class="literal">./foo</code> (even though
|
|||
|
|
<code class="literal">"${./foo} "</code> evaluates to
|
|||
|
|
<code class="literal">"/nix/store/<em class="replaceable"><code>hash</code></em>-foo "</code>).
|
|||
|
|
Nix now checks the type of antiquoted expressions and
|
|||
|
|
applies coercions.</p></li><li class="listitem"><p>Nix now shows the exact position of undefined variables. In
|
|||
|
|
particular, undefined variable errors in a <code class="literal">with</code>
|
|||
|
|
previously didn't show <span class="emphasis"><em>any</em></span> position
|
|||
|
|
information, so this makes it a lot easier to fix such
|
|||
|
|
errors.</p></li><li class="listitem"><p>Undefined variables are now treated consistently.
|
|||
|
|
Previously, the <code class="function">tryEval</code> function would catch
|
|||
|
|
undefined variables inside a <code class="literal">with</code> but not
|
|||
|
|
outside. Now <code class="function">tryEval</code> never catches undefined
|
|||
|
|
variables.</p></li><li class="listitem"><p>Bash completion in <span class="command"><strong>nix-shell</strong></span> now works
|
|||
|
|
correctly.</p></li><li class="listitem"><p>Stack traces are less verbose: they no longer show calls to
|
|||
|
|
builtin functions and only show a single line for each derivation
|
|||
|
|
on the call stack.</p></li><li class="listitem"><p>New built-in function: <code class="function">builtins.typeOf</code>,
|
|||
|
|
which returns the type of its argument as a string.</p></li></ul></div></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a id="ssec-relnotes-1.6.0"></a>C.12. Release 1.6 (2013-09-10)</h2></div></div></div><p>In addition to the usual bug fixes, this release has several new
|
|||
|
|
features:</p><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><p>The command <span class="command"><strong>nix-build --run-env</strong></span> has been
|
|||
|
|
renamed to <span class="command"><strong>nix-shell</strong></span>.</p></li><li class="listitem"><p><span class="command"><strong>nix-shell</strong></span> now sources
|
|||
|
|
<code class="filename">$stdenv/setup</code> <span class="emphasis"><em>inside</em></span> the
|
|||
|
|
interactive shell, rather than in a parent shell. This ensures
|
|||
|
|
that shell functions defined by <code class="literal">stdenv</code> can be
|
|||
|
|
used in the interactive shell.</p></li><li class="listitem"><p><span class="command"><strong>nix-shell</strong></span> has a new flag
|
|||
|
|
<code class="option">--pure</code> to clear the environment, so you get an
|
|||
|
|
environment that more closely corresponds to the “real” Nix build.
|
|||
|
|
</p></li><li class="listitem"><p><span class="command"><strong>nix-shell</strong></span> now sets the shell prompt
|
|||
|
|
(<code class="envar">PS1</code>) to ensure that Nix shells are distinguishable
|
|||
|
|
from your regular shells.</p></li><li class="listitem"><p><span class="command"><strong>nix-env</strong></span> no longer requires a
|
|||
|
|
<code class="literal">*</code> argument to match all packages, so
|
|||
|
|
<code class="literal">nix-env -qa</code> is equivalent to <code class="literal">nix-env
|
|||
|
|
-qa '*'</code>.</p></li><li class="listitem"><p><span class="command"><strong>nix-env -i</strong></span> has a new flag
|
|||
|
|
<code class="option">--remove-all</code> (<code class="option">-r</code>) to remove all
|
|||
|
|
previous packages from the profile. This makes it easier to do
|
|||
|
|
declarative package management similar to NixOS’s
|
|||
|
|
<code class="option">environment.systemPackages</code>. For instance, if you
|
|||
|
|
have a specification <code class="filename">my-packages.nix</code> like this:
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
with import <nixpkgs> {};
|
|||
|
|
[ thunderbird
|
|||
|
|
geeqie
|
|||
|
|
...
|
|||
|
|
]
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
then after any change to this file, you can run:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-env -f my-packages.nix -ir
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
to update your profile to match the specification.</p></li><li class="listitem"><p>The ‘<code class="literal">with</code>’ language construct is now more
|
|||
|
|
lazy. It only evaluates its argument if a variable might actually
|
|||
|
|
refer to an attribute in the argument. For instance, this now
|
|||
|
|
works:
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
let
|
|||
|
|
pkgs = with pkgs; { foo = "old"; bar = foo; } // overrides;
|
|||
|
|
overrides = { foo = "new"; };
|
|||
|
|
in pkgs.bar
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
This evaluates to <code class="literal">"new"</code>, while previously it
|
|||
|
|
gave an “infinite recursion” error.</p></li><li class="listitem"><p>Nix now has proper integer arithmetic operators. For
|
|||
|
|
instance, you can write <code class="literal">x + y</code> instead of
|
|||
|
|
<code class="literal">builtins.add x y</code>, or <code class="literal">x <
|
|||
|
|
y</code> instead of <code class="literal">builtins.lessThan x y</code>.
|
|||
|
|
The comparison operators also work on strings.</p></li><li class="listitem"><p>On 64-bit systems, Nix integers are now 64 bits rather than
|
|||
|
|
32 bits.</p></li><li class="listitem"><p>When using the Nix daemon, the <span class="command"><strong>nix-daemon</strong></span>
|
|||
|
|
worker process now runs on the same CPU as the client, on systems
|
|||
|
|
that support setting CPU affinity. This gives a significant speedup
|
|||
|
|
on some systems.</p></li><li class="listitem"><p>If a stack overflow occurs in the Nix evaluator, you now get
|
|||
|
|
a proper error message (rather than “Segmentation fault”) on some
|
|||
|
|
systems.</p></li><li class="listitem"><p>In addition to directories, you can now bind-mount regular
|
|||
|
|
files in chroots through the (now misnamed) option
|
|||
|
|
<code class="option">build-chroot-dirs</code>.</p></li></ul></div><p>This release has contributions from Domen Kožar, Eelco Dolstra,
|
|||
|
|
Florian Friesdorf, Gergely Risko, Ivan Kozik, Ludovic Courtès and Shea
|
|||
|
|
Levy.</p></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a id="ssec-relnotes-1.5.2"></a>C.13. Release 1.5.2 (2013-05-13)</h2></div></div></div><p>This is primarily a bug fix release. It has contributions from
|
|||
|
|
Eelco Dolstra, Lluís Batlle i Rossell and Shea Levy.</p></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a id="ssec-relnotes-1.5"></a>C.14. Release 1.5 (2013-02-27)</h2></div></div></div><p>This is a brown paper bag release to fix a regression introduced
|
|||
|
|
by the hard link security fix in 1.4.</p></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a id="ssec-relnotes-1.4"></a>C.15. Release 1.4 (2013-02-26)</h2></div></div></div><p>This release fixes a security bug in multi-user operation. It
|
|||
|
|
was possible for derivations to cause the mode of files outside of the
|
|||
|
|
Nix store to be changed to 444 (read-only but world-readable) by
|
|||
|
|
creating hard links to those files (<a class="link" href="https://github.com/NixOS/nix/commit/5526a282b5b44e9296e61e07d7d2626a79141ac4" target="_top">details</a>).</p><p>There are also the following improvements:</p><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><p>New built-in function:
|
|||
|
|
<code class="function">builtins.hashString</code>.</p></li><li class="listitem"><p>Build logs are now stored in
|
|||
|
|
<code class="filename">/nix/var/log/nix/drvs/<em class="replaceable"><code>XX</code></em>/</code>,
|
|||
|
|
where <em class="replaceable"><code>XX</code></em> is the first two characters of
|
|||
|
|
the derivation. This is useful on machines that keep a lot of build
|
|||
|
|
logs (such as Hydra servers).</p></li><li class="listitem"><p>The function <code class="function">corepkgs/fetchurl</code>
|
|||
|
|
can now make the downloaded file executable. This will allow
|
|||
|
|
getting rid of all bootstrap binaries in the Nixpkgs source
|
|||
|
|
tree.</p></li><li class="listitem"><p>Language change: The expression <code class="literal">"${./path}
|
|||
|
|
..."</code> now evaluates to a string instead of a
|
|||
|
|
path.</p></li></ul></div></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a id="ssec-relnotes-1.3"></a>C.16. Release 1.3 (2013-01-04)</h2></div></div></div><p>This is primarily a bug fix release. When this version is first
|
|||
|
|
run on Linux, it removes any immutable bits from the Nix store and
|
|||
|
|
increases the schema version of the Nix store. (The previous release
|
|||
|
|
removed support for setting the immutable bit; this release clears any
|
|||
|
|
remaining immutable bits to make certain operations more
|
|||
|
|
efficient.)</p><p>This release has contributions from Eelco Dolstra and Stuart
|
|||
|
|
Pernsteiner.</p></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a id="ssec-relnotes-1.2"></a>C.17. Release 1.2 (2012-12-06)</h2></div></div></div><p>This release has the following improvements and changes:</p><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><p>Nix has a new binary substituter mechanism: the
|
|||
|
|
<span class="emphasis"><em>binary cache</em></span>. A binary cache contains
|
|||
|
|
pre-built binaries of Nix packages. Whenever Nix wants to build a
|
|||
|
|
missing Nix store path, it will check a set of binary caches to
|
|||
|
|
see if any of them has a pre-built binary of that path. The
|
|||
|
|
configuration setting <code class="option">binary-caches</code> contains a
|
|||
|
|
list of URLs of binary caches. For instance, doing
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-env -i thunderbird --option binary-caches http://cache.nixos.org
|
|||
|
|
</pre><p>
|
|||
|
|
will install Thunderbird and its dependencies, using the available
|
|||
|
|
pre-built binaries in <code class="uri">http://cache.nixos.org</code>.
|
|||
|
|
The main advantage over the old “manifest”-based method of getting
|
|||
|
|
pre-built binaries is that you don’t have to worry about your
|
|||
|
|
manifest being in sync with the Nix expressions you’re installing
|
|||
|
|
from; i.e., you don’t need to run <span class="command"><strong>nix-pull</strong></span> to
|
|||
|
|
update your manifest. It’s also more scalable because you don’t
|
|||
|
|
need to redownload a giant manifest file every time.
|
|||
|
|
</p><p>A Nix channel can provide a binary cache URL that will be
|
|||
|
|
used automatically if you subscribe to that channel. If you use
|
|||
|
|
the Nixpkgs or NixOS channels
|
|||
|
|
(<code class="uri">http://nixos.org/channels</code>) you automatically get the
|
|||
|
|
cache <code class="uri">http://cache.nixos.org</code>.</p><p>Binary caches are created using <span class="command"><strong>nix-push</strong></span>.
|
|||
|
|
For details on the operation and format of binary caches, see the
|
|||
|
|
<span class="command"><strong>nix-push</strong></span> manpage. More details are provided in
|
|||
|
|
<a class="link" href="https://nixos.org/nix-dev/2012-September/009826.html" target="_top">this
|
|||
|
|
nix-dev posting</a>.</p></li><li class="listitem"><p>Multiple output support should now be usable. A derivation
|
|||
|
|
can declare that it wants to produce multiple store paths by
|
|||
|
|
saying something like
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
outputs = [ "lib" "headers" "doc" ];
|
|||
|
|
</pre><p>
|
|||
|
|
This will cause Nix to pass the intended store path of each output
|
|||
|
|
to the builder through the environment variables
|
|||
|
|
<code class="literal">lib</code>, <code class="literal">headers</code> and
|
|||
|
|
<code class="literal">doc</code>. Other packages can refer to a specific
|
|||
|
|
output by referring to
|
|||
|
|
<code class="literal"><em class="replaceable"><code>pkg</code></em>.<em class="replaceable"><code>output</code></em></code>,
|
|||
|
|
e.g.
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
buildInputs = [ pkg.lib pkg.headers ];
|
|||
|
|
</pre><p>
|
|||
|
|
If you install a package with multiple outputs using
|
|||
|
|
<span class="command"><strong>nix-env</strong></span>, each output path will be symlinked
|
|||
|
|
into the user environment.</p></li><li class="listitem"><p>Dashes are now valid as part of identifiers and attribute
|
|||
|
|
names.</p></li><li class="listitem"><p>The new operation <span class="command"><strong>nix-store --repair-path</strong></span>
|
|||
|
|
allows corrupted or missing store paths to be repaired by
|
|||
|
|
redownloading them. <span class="command"><strong>nix-store --verify --check-contents
|
|||
|
|
--repair</strong></span> will scan and repair all paths in the Nix
|
|||
|
|
store. Similarly, <span class="command"><strong>nix-env</strong></span>,
|
|||
|
|
<span class="command"><strong>nix-build</strong></span>, <span class="command"><strong>nix-instantiate</strong></span>
|
|||
|
|
and <span class="command"><strong>nix-store --realise</strong></span> have a
|
|||
|
|
<code class="option">--repair</code> flag to detect and fix bad paths by
|
|||
|
|
rebuilding or redownloading them.</p></li><li class="listitem"><p>Nix no longer sets the immutable bit on files in the Nix
|
|||
|
|
store. Instead, the recommended way to guard the Nix store
|
|||
|
|
against accidental modification on Linux is to make it a read-only
|
|||
|
|
bind mount, like this:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ mount --bind /nix/store /nix/store
|
|||
|
|
$ mount -o remount,ro,bind /nix/store
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
Nix will automatically make <code class="filename">/nix/store</code>
|
|||
|
|
writable as needed (using a private mount namespace) to allow
|
|||
|
|
modifications.</p></li><li class="listitem"><p>Store optimisation (replacing identical files in the store
|
|||
|
|
with hard links) can now be done automatically every time a path
|
|||
|
|
is added to the store. This is enabled by setting the
|
|||
|
|
configuration option <code class="literal">auto-optimise-store</code> to
|
|||
|
|
<code class="literal">true</code> (disabled by default).</p></li><li class="listitem"><p>Nix now supports <span class="command"><strong>xz</strong></span> compression for NARs
|
|||
|
|
in addition to <span class="command"><strong>bzip2</strong></span>. It compresses about 30%
|
|||
|
|
better on typical archives and decompresses about twice as
|
|||
|
|
fast.</p></li><li class="listitem"><p>Basic Nix expression evaluation profiling: setting the
|
|||
|
|
environment variable <code class="envar">NIX_COUNT_CALLS</code> to
|
|||
|
|
<code class="literal">1</code> will cause Nix to print how many times each
|
|||
|
|
primop or function was executed.</p></li><li class="listitem"><p>New primops: <code class="varname">concatLists</code>,
|
|||
|
|
<code class="varname">elem</code>, <code class="varname">elemAt</code> and
|
|||
|
|
<code class="varname">filter</code>.</p></li><li class="listitem"><p>The command <span class="command"><strong>nix-copy-closure</strong></span> has a new
|
|||
|
|
flag <code class="option">--use-substitutes</code> (<code class="option">-s</code>) to
|
|||
|
|
download missing paths on the target machine using the substitute
|
|||
|
|
mechanism.</p></li><li class="listitem"><p>The command <span class="command"><strong>nix-worker</strong></span> has been renamed
|
|||
|
|
to <span class="command"><strong>nix-daemon</strong></span>. Support for running the Nix
|
|||
|
|
worker in “slave” mode has been removed.</p></li><li class="listitem"><p>The <code class="option">--help</code> flag of every Nix command now
|
|||
|
|
invokes <span class="command"><strong>man</strong></span>.</p></li><li class="listitem"><p>Chroot builds are now supported on systemd machines.</p></li></ul></div><p>This release has contributions from Eelco Dolstra, Florian
|
|||
|
|
Friesdorf, Mats Erik Andersson and Shea Levy.</p></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a id="ssec-relnotes-1.1"></a>C.18. Release 1.1 (2012-07-18)</h2></div></div></div><p>This release has the following improvements:</p><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><p>On Linux, when doing a chroot build, Nix now uses various
|
|||
|
|
namespace features provided by the Linux kernel to improve
|
|||
|
|
build isolation. Namely:
|
|||
|
|
</p><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: circle; "><li class="listitem"><p>The private network namespace ensures that
|
|||
|
|
builders cannot talk to the outside world (or vice versa): each
|
|||
|
|
build only sees a private loopback interface. This also means
|
|||
|
|
that two concurrent builds can listen on the same port (e.g. as
|
|||
|
|
part of a test) without conflicting with each
|
|||
|
|
other.</p></li><li class="listitem"><p>The PID namespace causes each build to start as
|
|||
|
|
PID 1. Processes outside of the chroot are not visible to those
|
|||
|
|
on the inside. On the other hand, processes inside the chroot
|
|||
|
|
<span class="emphasis"><em>are</em></span> visible from the outside (though with
|
|||
|
|
different PIDs).</p></li><li class="listitem"><p>The IPC namespace prevents the builder from
|
|||
|
|
communicating with outside processes using SysV IPC mechanisms
|
|||
|
|
(shared memory, message queues, semaphores). It also ensures
|
|||
|
|
that all IPC objects are destroyed when the builder
|
|||
|
|
exits.</p></li><li class="listitem"><p>The UTS namespace ensures that builders see a
|
|||
|
|
hostname of <code class="literal">localhost</code> rather than the actual
|
|||
|
|
hostname.</p></li><li class="listitem"><p>The private mount namespace was already used by
|
|||
|
|
Nix to ensure that the bind-mounts used to set up the chroot are
|
|||
|
|
cleaned up automatically.</p></li></ul></div><p>
|
|||
|
|
</p></li><li class="listitem"><p>Build logs are now compressed using
|
|||
|
|
<span class="command"><strong>bzip2</strong></span>. The command <span class="command"><strong>nix-store
|
|||
|
|
-l</strong></span> decompresses them on the fly. This can be disabled
|
|||
|
|
by setting the option <code class="literal">build-compress-log</code> to
|
|||
|
|
<code class="literal">false</code>.</p></li><li class="listitem"><p>The creation of build logs in
|
|||
|
|
<code class="filename">/nix/var/log/nix/drvs</code> can be disabled by
|
|||
|
|
setting the new option <code class="literal">build-keep-log</code> to
|
|||
|
|
<code class="literal">false</code>. This is useful, for instance, for Hydra
|
|||
|
|
build machines.</p></li><li class="listitem"><p>Nix now reserves some space in
|
|||
|
|
<code class="filename">/nix/var/nix/db/reserved</code> to ensure that the
|
|||
|
|
garbage collector can run successfully if the disk is full. This
|
|||
|
|
is necessary because SQLite transactions fail if the disk is
|
|||
|
|
full.</p></li><li class="listitem"><p>Added a basic <code class="function">fetchurl</code> function. This
|
|||
|
|
is not intended to replace the <code class="function">fetchurl</code> in
|
|||
|
|
Nixpkgs, but is useful for bootstrapping; e.g., it will allow us
|
|||
|
|
to get rid of the bootstrap binaries in the Nixpkgs source tree
|
|||
|
|
and download them instead. You can use it by doing
|
|||
|
|
<code class="literal">import <nix/fetchurl.nix> { url =
|
|||
|
|
<em class="replaceable"><code>url</code></em>; sha256 =
|
|||
|
|
"<em class="replaceable"><code>hash</code></em>"; }</code>. (Shea Levy)</p></li><li class="listitem"><p>Improved RPM spec file. (Michel Alexandre Salim)</p></li><li class="listitem"><p>Support for on-demand socket-based activation in the Nix
|
|||
|
|
daemon with <span class="command"><strong>systemd</strong></span>.</p></li><li class="listitem"><p>Added a manpage for
|
|||
|
|
<span class="citerefentry"><span class="refentrytitle">nix.conf</span>(5)</span>.</p></li><li class="listitem"><p>When using the Nix daemon, the <code class="option">-s</code> flag in
|
|||
|
|
<span class="command"><strong>nix-env -qa</strong></span> is now much faster.</p></li></ul></div></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a id="ssec-relnotes-1.0"></a>C.19. Release 1.0 (2012-05-11)</h2></div></div></div><p>There have been numerous improvements and bug fixes since the
|
|||
|
|
previous release. Here are the most significant:</p><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><p>Nix can now optionally use the Boehm garbage collector.
|
|||
|
|
This significantly reduces the Nix evaluator’s memory footprint,
|
|||
|
|
especially when evaluating large NixOS system configurations. It
|
|||
|
|
can be enabled using the <code class="option">--enable-gc</code> configure
|
|||
|
|
option.</p></li><li class="listitem"><p>Nix now uses SQLite for its database. This is faster and
|
|||
|
|
more flexible than the old <span class="emphasis"><em>ad hoc</em></span> format.
|
|||
|
|
SQLite is also used to cache the manifests in
|
|||
|
|
<code class="filename">/nix/var/nix/manifests</code>, resulting in a
|
|||
|
|
significant speedup.</p></li><li class="listitem"><p>Nix now has an search path for expressions. The search path
|
|||
|
|
is set using the environment variable <code class="envar">NIX_PATH</code> and
|
|||
|
|
the <code class="option">-I</code> command line option. In Nix expressions,
|
|||
|
|
paths between angle brackets are used to specify files that must
|
|||
|
|
be looked up in the search path. For instance, the expression
|
|||
|
|
<code class="literal"><nixpkgs/default.nix></code> looks for a file
|
|||
|
|
<code class="filename">nixpkgs/default.nix</code> relative to every element
|
|||
|
|
in the search path.</p></li><li class="listitem"><p>The new command <span class="command"><strong>nix-build --run-env</strong></span>
|
|||
|
|
builds all dependencies of a derivation, then starts a shell in an
|
|||
|
|
environment containing all variables from the derivation. This is
|
|||
|
|
useful for reproducing the environment of a derivation for
|
|||
|
|
development.</p></li><li class="listitem"><p>The new command <span class="command"><strong>nix-store --verify-path</strong></span>
|
|||
|
|
verifies that the contents of a store path have not
|
|||
|
|
changed.</p></li><li class="listitem"><p>The new command <span class="command"><strong>nix-store --print-env</strong></span>
|
|||
|
|
prints out the environment of a derivation in a format that can be
|
|||
|
|
evaluated by a shell.</p></li><li class="listitem"><p>Attribute names can now be arbitrary strings. For instance,
|
|||
|
|
you can write <code class="literal">{ "foo-1.2" = …; "bla bla" = …; }."bla
|
|||
|
|
bla"</code>.</p></li><li class="listitem"><p>Attribute selection can now provide a default value using
|
|||
|
|
the <code class="literal">or</code> operator. For instance, the expression
|
|||
|
|
<code class="literal">x.y.z or e</code> evaluates to the attribute
|
|||
|
|
<code class="literal">x.y.z</code> if it exists, and <code class="literal">e</code>
|
|||
|
|
otherwise.</p></li><li class="listitem"><p>The right-hand side of the <code class="literal">?</code> operator can
|
|||
|
|
now be an attribute path, e.g., <code class="literal">attrs ?
|
|||
|
|
a.b.c</code>.</p></li><li class="listitem"><p>On Linux, Nix will now make files in the Nix store immutable
|
|||
|
|
on filesystems that support it. This prevents accidental
|
|||
|
|
modification of files in the store by the root user.</p></li><li class="listitem"><p>Nix has preliminary support for derivations with multiple
|
|||
|
|
outputs. This is useful because it allows parts of a package to
|
|||
|
|
be deployed and garbage-collected separately. For instance,
|
|||
|
|
development parts of a package such as header files or static
|
|||
|
|
libraries would typically not be part of the closure of an
|
|||
|
|
application, resulting in reduced disk usage and installation
|
|||
|
|
time.</p></li><li class="listitem"><p>The Nix store garbage collector is faster and holds the
|
|||
|
|
global lock for a shorter amount of time.</p></li><li class="listitem"><p>The option <code class="option">--timeout</code> (corresponding to the
|
|||
|
|
configuration setting <code class="literal">build-timeout</code>) allows you
|
|||
|
|
to set an absolute timeout on builds — if a build runs for more than
|
|||
|
|
the given number of seconds, it is terminated. This is useful for
|
|||
|
|
recovering automatically from builds that are stuck in an infinite
|
|||
|
|
loop but keep producing output, and for which
|
|||
|
|
<code class="literal">--max-silent-time</code> is ineffective.</p></li><li class="listitem"><p>Nix development has moved to GitHub (<a class="link" href="https://github.com/NixOS/nix" target="_top">https://github.com/NixOS/nix</a>).</p></li></ul></div></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a id="ssec-relnotes-0.16"></a>C.20. Release 0.16 (2010-08-17)</h2></div></div></div><p>This release has the following improvements:</p><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><p>The Nix expression evaluator is now much faster in most
|
|||
|
|
cases: typically, <a class="link" href="http://www.mail-archive.com/nix-dev@cs.uu.nl/msg04113.html" target="_top">3
|
|||
|
|
to 8 times compared to the old implementation</a>. It also
|
|||
|
|
uses less memory. It no longer depends on the ATerm
|
|||
|
|
library.</p></li><li class="listitem"><p>
|
|||
|
|
Support for configurable parallelism inside builders. Build
|
|||
|
|
scripts have always had the ability to perform multiple build
|
|||
|
|
actions in parallel (for instance, by running <span class="command"><strong>make -j
|
|||
|
|
2</strong></span>), but this was not desirable because the number of
|
|||
|
|
actions to be performed in parallel was not configurable. Nix
|
|||
|
|
now has an option <code class="option">--cores
|
|||
|
|
<em class="replaceable"><code>N</code></em></code> as well as a configuration
|
|||
|
|
setting <code class="varname">build-cores =
|
|||
|
|
<em class="replaceable"><code>N</code></em></code> that causes the
|
|||
|
|
environment variable <code class="envar">NIX_BUILD_CORES</code> to be set to
|
|||
|
|
<em class="replaceable"><code>N</code></em> when the builder is invoked. The
|
|||
|
|
builder can use this at its discretion to perform a parallel
|
|||
|
|
build, e.g., by calling <span class="command"><strong>make -j
|
|||
|
|
<em class="replaceable"><code>N</code></em></strong></span>. In Nixpkgs, this can be
|
|||
|
|
enabled on a per-package basis by setting the derivation
|
|||
|
|
attribute <code class="varname">enableParallelBuilding</code> to
|
|||
|
|
<code class="literal">true</code>.
|
|||
|
|
</p></li><li class="listitem"><p><span class="command"><strong>nix-store -q</strong></span> now supports XML output
|
|||
|
|
through the <code class="option">--xml</code> flag.</p></li><li class="listitem"><p>Several bug fixes.</p></li></ul></div></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a id="ssec-relnotes-0.15"></a>C.21. Release 0.15 (2010-03-17)</h2></div></div></div><p>This is a bug-fix release. Among other things, it fixes
|
|||
|
|
building on Mac OS X (Snow Leopard), and improves the contents of
|
|||
|
|
<code class="filename">/etc/passwd</code> and <code class="filename">/etc/group</code>
|
|||
|
|
in <code class="literal">chroot</code> builds.</p></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a id="ssec-relnotes-0.14"></a>C.22. Release 0.14 (2010-02-04)</h2></div></div></div><p>This release has the following improvements:</p><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><p>The garbage collector now starts deleting garbage much
|
|||
|
|
faster than before. It no longer determines liveness of all paths
|
|||
|
|
in the store, but does so on demand.</p></li><li class="listitem"><p>Added a new operation, <span class="command"><strong>nix-store --query
|
|||
|
|
--roots</strong></span>, that shows the garbage collector roots that
|
|||
|
|
directly or indirectly point to the given store paths.</p></li><li class="listitem"><p>Removed support for converting Berkeley DB-based Nix
|
|||
|
|
databases to the new schema.</p></li><li class="listitem"><p>Removed the <code class="option">--use-atime</code> and
|
|||
|
|
<code class="option">--max-atime</code> garbage collector options. They were
|
|||
|
|
not very useful in practice.</p></li><li class="listitem"><p>On Windows, Nix now requires Cygwin 1.7.x.</p></li><li class="listitem"><p>A few bug fixes.</p></li></ul></div></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a id="ssec-relnotes-0.13"></a>C.23. Release 0.13 (2009-11-05)</h2></div></div></div><p>This is primarily a bug fix release. It has some new
|
|||
|
|
features:</p><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><p>Syntactic sugar for writing nested attribute sets. Instead of
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
{
|
|||
|
|
foo = {
|
|||
|
|
bar = 123;
|
|||
|
|
xyzzy = true;
|
|||
|
|
};
|
|||
|
|
a = { b = { c = "d"; }; };
|
|||
|
|
}
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
you can write
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
{
|
|||
|
|
foo.bar = 123;
|
|||
|
|
foo.xyzzy = true;
|
|||
|
|
a.b.c = "d";
|
|||
|
|
}
|
|||
|
|
</pre><p>
|
|||
|
|
|
|||
|
|
This is useful, for instance, in NixOS configuration files.</p></li><li class="listitem"><p>Support for Nix channels generated by Hydra, the Nix-based
|
|||
|
|
continuous build system. (Hydra generates NAR archives on the
|
|||
|
|
fly, so the size and hash of these archives isn’t known in
|
|||
|
|
advance.)</p></li><li class="listitem"><p>Support <code class="literal">i686-linux</code> builds directly on
|
|||
|
|
<code class="literal">x86_64-linux</code> Nix installations. This is
|
|||
|
|
implemented using the <code class="function">personality()</code> syscall,
|
|||
|
|
which causes <span class="command"><strong>uname</strong></span> to return
|
|||
|
|
<code class="literal">i686</code> in child processes.</p></li><li class="listitem"><p>Various improvements to the <code class="literal">chroot</code>
|
|||
|
|
support. Building in a <code class="literal">chroot</code> works quite well
|
|||
|
|
now.</p></li><li class="listitem"><p>Nix no longer blocks if it tries to build a path and another
|
|||
|
|
process is already building the same path. Instead it tries to
|
|||
|
|
build another buildable path first. This improves
|
|||
|
|
parallelism.</p></li><li class="listitem"><p>Support for large (> 4 GiB) files in NAR archives.</p></li><li class="listitem"><p>Various (performance) improvements to the remote build
|
|||
|
|
mechanism.</p></li><li class="listitem"><p>New primops: <code class="varname">builtins.addErrorContext</code> (to
|
|||
|
|
add a string to stack traces — useful for debugging),
|
|||
|
|
<code class="varname">builtins.isBool</code>,
|
|||
|
|
<code class="varname">builtins.isString</code>,
|
|||
|
|
<code class="varname">builtins.isInt</code>,
|
|||
|
|
<code class="varname">builtins.intersectAttrs</code>.</p></li><li class="listitem"><p>OpenSolaris support (Sander van der Burg).</p></li><li class="listitem"><p>Stack traces are no longer displayed unless the
|
|||
|
|
<code class="option">--show-trace</code> option is used.</p></li><li class="listitem"><p>The scoping rules for <code class="literal">inherit
|
|||
|
|
(<em class="replaceable"><code>e</code></em>) ...</code> in recursive
|
|||
|
|
attribute sets have changed. The expression
|
|||
|
|
<em class="replaceable"><code>e</code></em> can now refer to the attributes
|
|||
|
|
defined in the containing set.</p></li></ul></div></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a id="ssec-relnotes-0.12"></a>C.24. Release 0.12 (2008-11-20)</h2></div></div></div><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><p>Nix no longer uses Berkeley DB to store Nix store metadata.
|
|||
|
|
The principal advantages of the new storage scheme are: it works
|
|||
|
|
properly over decent implementations of NFS (allowing Nix stores
|
|||
|
|
to be shared between multiple machines); no recovery is needed
|
|||
|
|
when a Nix process crashes; no write access is needed for
|
|||
|
|
read-only operations; no more running out of Berkeley DB locks on
|
|||
|
|
certain operations.</p><p>You still need to compile Nix with Berkeley DB support if
|
|||
|
|
you want Nix to automatically convert your old Nix store to the
|
|||
|
|
new schema. If you don’t need this, you can build Nix with the
|
|||
|
|
<code class="filename">configure</code> option
|
|||
|
|
<code class="option">--disable-old-db-compat</code>.</p><p>After the automatic conversion to the new schema, you can
|
|||
|
|
delete the old Berkeley DB files:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ cd /nix/var/nix/db
|
|||
|
|
$ rm __db* log.* derivers references referrers reserved validpaths DB_CONFIG</pre><p>
|
|||
|
|
|
|||
|
|
The new metadata is stored in the directories
|
|||
|
|
<code class="filename">/nix/var/nix/db/info</code> and
|
|||
|
|
<code class="filename">/nix/var/nix/db/referrer</code>. Though the
|
|||
|
|
metadata is stored in human-readable plain-text files, they are
|
|||
|
|
not intended to be human-editable, as Nix is rather strict about
|
|||
|
|
the format.</p><p>The new storage schema may or may not require less disk
|
|||
|
|
space than the Berkeley DB environment, mostly depending on the
|
|||
|
|
cluster size of your file system. With 1 KiB clusters (which
|
|||
|
|
seems to be the <code class="literal">ext3</code> default nowadays) it
|
|||
|
|
usually takes up much less space.</p></li><li class="listitem"><p>There is a new substituter that copies paths
|
|||
|
|
directly from other (remote) Nix stores mounted somewhere in the
|
|||
|
|
filesystem. For instance, you can speed up an installation by
|
|||
|
|
mounting some remote Nix store that already has the packages in
|
|||
|
|
question via NFS or <code class="literal">sshfs</code>. The environment
|
|||
|
|
variable <code class="envar">NIX_OTHER_STORES</code> specifies the locations of
|
|||
|
|
the remote Nix directories,
|
|||
|
|
e.g. <code class="literal">/mnt/remote-fs/nix</code>.</p></li><li class="listitem"><p>New <span class="command"><strong>nix-store</strong></span> operations
|
|||
|
|
<code class="option">--dump-db</code> and <code class="option">--load-db</code> to dump
|
|||
|
|
and reload the Nix database.</p></li><li class="listitem"><p>The garbage collector has a number of new options to
|
|||
|
|
allow only some of the garbage to be deleted. The option
|
|||
|
|
<code class="option">--max-freed <em class="replaceable"><code>N</code></em></code> tells the
|
|||
|
|
collector to stop after at least <em class="replaceable"><code>N</code></em> bytes
|
|||
|
|
have been deleted. The option <code class="option">--max-links
|
|||
|
|
<em class="replaceable"><code>N</code></em></code> tells it to stop after the
|
|||
|
|
link count on <code class="filename">/nix/store</code> has dropped below
|
|||
|
|
<em class="replaceable"><code>N</code></em>. This is useful for very large Nix
|
|||
|
|
stores on filesystems with a 32000 subdirectories limit (like
|
|||
|
|
<code class="literal">ext3</code>). The option <code class="option">--use-atime</code>
|
|||
|
|
causes store paths to be deleted in order of ascending last access
|
|||
|
|
time. This allows non-recently used stuff to be deleted. The
|
|||
|
|
option <code class="option">--max-atime <em class="replaceable"><code>time</code></em></code>
|
|||
|
|
specifies an upper limit to the last accessed time of paths that may
|
|||
|
|
be deleted. For instance,
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-store --gc -v --max-atime $(date +%s -d "2 months ago")</pre><p>
|
|||
|
|
|
|||
|
|
deletes everything that hasn’t been accessed in two months.</p></li><li class="listitem"><p><span class="command"><strong>nix-env</strong></span> now uses optimistic
|
|||
|
|
profile locking when performing an operation like installing or
|
|||
|
|
upgrading, instead of setting an exclusive lock on the profile.
|
|||
|
|
This allows multiple <span class="command"><strong>nix-env -i / -u / -e</strong></span>
|
|||
|
|
operations on the same profile in parallel. If a
|
|||
|
|
<span class="command"><strong>nix-env</strong></span> operation sees at the end that the profile
|
|||
|
|
was changed in the meantime by another process, it will just
|
|||
|
|
restart. This is generally cheap because the build results are
|
|||
|
|
still in the Nix store.</p></li><li class="listitem"><p>The option <code class="option">--dry-run</code> is now
|
|||
|
|
supported by <span class="command"><strong>nix-store -r</strong></span> and
|
|||
|
|
<span class="command"><strong>nix-build</strong></span>.</p></li><li class="listitem"><p>The information previously shown by
|
|||
|
|
<code class="option">--dry-run</code> (i.e., which derivations will be built
|
|||
|
|
and which paths will be substituted) is now always shown by
|
|||
|
|
<span class="command"><strong>nix-env</strong></span>, <span class="command"><strong>nix-store -r</strong></span> and
|
|||
|
|
<span class="command"><strong>nix-build</strong></span>. The total download size of
|
|||
|
|
substitutable paths is now also shown. For instance, a build will
|
|||
|
|
show something like
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
the following derivations will be built:
|
|||
|
|
/nix/store/129sbxnk5n466zg6r1qmq1xjv9zymyy7-activate-configuration.sh.drv
|
|||
|
|
/nix/store/7mzy971rdm8l566ch8hgxaf89x7lr7ik-upstart-jobs.drv
|
|||
|
|
...
|
|||
|
|
the following paths will be downloaded/copied (30.02 MiB):
|
|||
|
|
/nix/store/4m8pvgy2dcjgppf5b4cj5l6wyshjhalj-samba-3.2.4
|
|||
|
|
/nix/store/7h1kwcj29ip8vk26rhmx6bfjraxp0g4l-libunwind-0.98.6
|
|||
|
|
...</pre><p>
|
|||
|
|
|
|||
|
|
</p></li><li class="listitem"><p>Language features:
|
|||
|
|
|
|||
|
|
</p><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: circle; "><li class="listitem"><p>@-patterns as in Haskell. For instance, in a
|
|||
|
|
function definition
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">f = args @ {x, y, z}: <em class="replaceable"><code>...</code></em>;</pre><p>
|
|||
|
|
|
|||
|
|
<code class="varname">args</code> refers to the argument as a whole, which
|
|||
|
|
is further pattern-matched against the attribute set pattern
|
|||
|
|
<code class="literal">{x, y, z}</code>.</p></li><li class="listitem"><p>“<code class="literal">...</code>” (ellipsis) patterns.
|
|||
|
|
An attribute set pattern can now say <code class="literal">...</code> at
|
|||
|
|
the end of the attribute name list to specify that the function
|
|||
|
|
takes <span class="emphasis"><em>at least</em></span> the listed attributes, while
|
|||
|
|
ignoring additional attributes. For instance,
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">{stdenv, fetchurl, fuse, ...}: <em class="replaceable"><code>...</code></em></pre><p>
|
|||
|
|
|
|||
|
|
defines a function that accepts any attribute set that includes
|
|||
|
|
at least the three listed attributes.</p></li><li class="listitem"><p>New primops:
|
|||
|
|
<code class="varname">builtins.parseDrvName</code> (split a package name
|
|||
|
|
string like <code class="literal">"nix-0.12pre12876"</code> into its name
|
|||
|
|
and version components, e.g. <code class="literal">"nix"</code> and
|
|||
|
|
<code class="literal">"0.12pre12876"</code>),
|
|||
|
|
<code class="varname">builtins.compareVersions</code> (compare two version
|
|||
|
|
strings using the same algorithm that <span class="command"><strong>nix-env</strong></span>
|
|||
|
|
uses), <code class="varname">builtins.length</code> (efficiently compute
|
|||
|
|
the length of a list), <code class="varname">builtins.mul</code> (integer
|
|||
|
|
multiplication), <code class="varname">builtins.div</code> (integer
|
|||
|
|
division).
|
|||
|
|
|
|||
|
|
</p></li></ul></div><p>
|
|||
|
|
|
|||
|
|
</p></li><li class="listitem"><p><span class="command"><strong>nix-prefetch-url</strong></span> now supports
|
|||
|
|
<code class="literal">mirror://</code> URLs, provided that the environment
|
|||
|
|
variable <code class="envar">NIXPKGS_ALL</code> points at a Nixpkgs
|
|||
|
|
tree.</p></li><li class="listitem"><p>Removed the commands
|
|||
|
|
<span class="command"><strong>nix-pack-closure</strong></span> and
|
|||
|
|
<span class="command"><strong>nix-unpack-closure</strong></span>. You can do almost the same
|
|||
|
|
thing but much more efficiently by doing <code class="literal">nix-store --export
|
|||
|
|
$(nix-store -qR <em class="replaceable"><code>paths</code></em>) > closure</code> and
|
|||
|
|
<code class="literal">nix-store --import <
|
|||
|
|
closure</code>.</p></li><li class="listitem"><p>Lots of bug fixes, including a big performance bug in
|
|||
|
|
the handling of <code class="literal">with</code>-expressions.</p></li></ul></div></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a id="ssec-relnotes-0.11"></a>C.25. Release 0.11 (2007-12-31)</h2></div></div></div><p>Nix 0.11 has many improvements over the previous stable release.
|
|||
|
|
The most important improvement is secure multi-user support. It also
|
|||
|
|
features many usability enhancements and language extensions, many of
|
|||
|
|
them prompted by NixOS, the purely functional Linux distribution based
|
|||
|
|
on Nix. Here is an (incomplete) list:</p><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><p>Secure multi-user support. A single Nix store can
|
|||
|
|
now be shared between multiple (possible untrusted) users. This is
|
|||
|
|
an important feature for NixOS, where it allows non-root users to
|
|||
|
|
install software. The old setuid method for sharing a store between
|
|||
|
|
multiple users has been removed. Details for setting up a
|
|||
|
|
multi-user store can be found in the manual.</p></li><li class="listitem"><p>The new command <span class="command"><strong>nix-copy-closure</strong></span>
|
|||
|
|
gives you an easy and efficient way to exchange software between
|
|||
|
|
machines. It copies the missing parts of the closure of a set of
|
|||
|
|
store path to or from a remote machine via
|
|||
|
|
<span class="command"><strong>ssh</strong></span>.</p></li><li class="listitem"><p>A new kind of string literal: strings between double
|
|||
|
|
single-quotes (<code class="literal">''</code>) have indentation
|
|||
|
|
“intelligently” removed. This allows large strings (such as shell
|
|||
|
|
scripts or configuration file fragments in NixOS) to cleanly follow
|
|||
|
|
the indentation of the surrounding expression. It also requires
|
|||
|
|
much less escaping, since <code class="literal">''</code> is less common in
|
|||
|
|
most languages than <code class="literal">"</code>.</p></li><li class="listitem"><p><span class="command"><strong>nix-env</strong></span> <code class="option">--set</code>
|
|||
|
|
modifies the current generation of a profile so that it contains
|
|||
|
|
exactly the specified derivation, and nothing else. For example,
|
|||
|
|
<code class="literal">nix-env -p /nix/var/nix/profiles/browser --set
|
|||
|
|
firefox</code> lets the profile named
|
|||
|
|
<code class="filename">browser</code> contain just Firefox.</p></li><li class="listitem"><p><span class="command"><strong>nix-env</strong></span> now maintains
|
|||
|
|
meta-information about installed packages in profiles. The
|
|||
|
|
meta-information is the contents of the <code class="varname">meta</code>
|
|||
|
|
attribute of derivations, such as <code class="varname">description</code> or
|
|||
|
|
<code class="varname">homepage</code>. The command <code class="literal">nix-env -q --xml
|
|||
|
|
--meta</code> shows all meta-information.</p></li><li class="listitem"><p><span class="command"><strong>nix-env</strong></span> now uses the
|
|||
|
|
<code class="varname">meta.priority</code> attribute of derivations to resolve
|
|||
|
|
filename collisions between packages. Lower priority values denote
|
|||
|
|
a higher priority. For instance, the GCC wrapper package and the
|
|||
|
|
Binutils package in Nixpkgs both have a file
|
|||
|
|
<code class="filename">bin/ld</code>, so previously if you tried to install
|
|||
|
|
both you would get a collision. Now, on the other hand, the GCC
|
|||
|
|
wrapper declares a higher priority than Binutils, so the former’s
|
|||
|
|
<code class="filename">bin/ld</code> is symlinked in the user
|
|||
|
|
environment.</p></li><li class="listitem"><p><span class="command"><strong>nix-env -i / -u</strong></span>: instead of
|
|||
|
|
breaking package ties by version, break them by priority and version
|
|||
|
|
number. That is, if there are multiple packages with the same name,
|
|||
|
|
then pick the package with the highest priority, and only use the
|
|||
|
|
version if there are multiple packages with the same
|
|||
|
|
priority.</p><p>This makes it possible to mark specific versions/variant in
|
|||
|
|
Nixpkgs more or less desirable than others. A typical example would
|
|||
|
|
be a beta version of some package (e.g.,
|
|||
|
|
<code class="literal">gcc-4.2.0rc1</code>) which should not be installed even
|
|||
|
|
though it is the highest version, except when it is explicitly
|
|||
|
|
selected (e.g., <code class="literal">nix-env -i
|
|||
|
|
gcc-4.2.0rc1</code>).</p></li><li class="listitem"><p><span class="command"><strong>nix-env --set-flag</strong></span> allows meta
|
|||
|
|
attributes of installed packages to be modified. There are several
|
|||
|
|
attributes that can be usefully modified, because they affect the
|
|||
|
|
behaviour of <span class="command"><strong>nix-env</strong></span> or the user environment
|
|||
|
|
build script:
|
|||
|
|
|
|||
|
|
</p><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: circle; "><li class="listitem"><p><code class="varname">meta.priority</code> can be changed
|
|||
|
|
to resolve filename clashes (see above).</p></li><li class="listitem"><p><code class="varname">meta.keep</code> can be set to
|
|||
|
|
<code class="literal">true</code> to prevent the package from being
|
|||
|
|
upgraded or replaced. Useful if you want to hang on to an older
|
|||
|
|
version of a package.</p></li><li class="listitem"><p><code class="varname">meta.active</code> can be set to
|
|||
|
|
<code class="literal">false</code> to “disable” the package. That is, no
|
|||
|
|
symlinks will be generated to the files of the package, but it
|
|||
|
|
remains part of the profile (so it won’t be garbage-collected).
|
|||
|
|
Set it back to <code class="literal">true</code> to re-enable the
|
|||
|
|
package.</p></li></ul></div><p>
|
|||
|
|
|
|||
|
|
</p></li><li class="listitem"><p><span class="command"><strong>nix-env -q</strong></span> now has a flag
|
|||
|
|
<code class="option">--prebuilt-only</code> (<code class="option">-b</code>) that causes
|
|||
|
|
<span class="command"><strong>nix-env</strong></span> to show only those derivations whose
|
|||
|
|
output is already in the Nix store or that can be substituted (i.e.,
|
|||
|
|
downloaded from somewhere). In other words, it shows the packages
|
|||
|
|
that can be installed “quickly”, i.e., don’t need to be built from
|
|||
|
|
source. The <code class="option">-b</code> flag is also available in
|
|||
|
|
<span class="command"><strong>nix-env -i</strong></span> and <span class="command"><strong>nix-env -u</strong></span> to
|
|||
|
|
filter out derivations for which no pre-built binary is
|
|||
|
|
available.</p></li><li class="listitem"><p>The new option <code class="option">--argstr</code> (in
|
|||
|
|
<span class="command"><strong>nix-env</strong></span>, <span class="command"><strong>nix-instantiate</strong></span> and
|
|||
|
|
<span class="command"><strong>nix-build</strong></span>) is like <code class="option">--arg</code>, except
|
|||
|
|
that the value is a string. For example, <code class="literal">--argstr system
|
|||
|
|
i686-linux</code> is equivalent to <code class="literal">--arg system
|
|||
|
|
\"i686-linux\"</code> (note that <code class="option">--argstr</code>
|
|||
|
|
prevents annoying quoting around shell arguments).</p></li><li class="listitem"><p><span class="command"><strong>nix-store</strong></span> has a new operation
|
|||
|
|
<code class="option">--read-log</code> (<code class="option">-l</code>)
|
|||
|
|
<em class="parameter"><code>paths</code></em> that shows the build log of the given
|
|||
|
|
paths.</p></li><li class="listitem"><p>Nix now uses Berkeley DB 4.5. The database is
|
|||
|
|
upgraded automatically, but you should be careful not to use old
|
|||
|
|
versions of Nix that still use Berkeley DB 4.4.</p></li><li class="listitem"><p>The option <code class="option">--max-silent-time</code>
|
|||
|
|
(corresponding to the configuration setting
|
|||
|
|
<code class="literal">build-max-silent-time</code>) allows you to set a
|
|||
|
|
timeout on builds — if a build produces no output on
|
|||
|
|
<code class="literal">stdout</code> or <code class="literal">stderr</code> for the given
|
|||
|
|
number of seconds, it is terminated. This is useful for recovering
|
|||
|
|
automatically from builds that are stuck in an infinite
|
|||
|
|
loop.</p></li><li class="listitem"><p><span class="command"><strong>nix-channel</strong></span>: each subscribed
|
|||
|
|
channel is its own attribute in the top-level expression generated
|
|||
|
|
for the channel. This allows disambiguation (e.g. <code class="literal">nix-env
|
|||
|
|
-i -A nixpkgs_unstable.firefox</code>).</p></li><li class="listitem"><p>The substitutes table has been removed from the
|
|||
|
|
database. This makes operations such as <span class="command"><strong>nix-pull</strong></span>
|
|||
|
|
and <span class="command"><strong>nix-channel --update</strong></span> much, much
|
|||
|
|
faster.</p></li><li class="listitem"><p><span class="command"><strong>nix-pull</strong></span> now supports
|
|||
|
|
bzip2-compressed manifests. This speeds up
|
|||
|
|
channels.</p></li><li class="listitem"><p><span class="command"><strong>nix-prefetch-url</strong></span> now has a
|
|||
|
|
limited form of caching. This is used by
|
|||
|
|
<span class="command"><strong>nix-channel</strong></span> to prevent unnecessary downloads when
|
|||
|
|
the channel hasn’t changed.</p></li><li class="listitem"><p><span class="command"><strong>nix-prefetch-url</strong></span> now by default
|
|||
|
|
computes the SHA-256 hash of the file instead of the MD5 hash. In
|
|||
|
|
calls to <code class="function">fetchurl</code> you should pass the
|
|||
|
|
<code class="literal">sha256</code> attribute instead of
|
|||
|
|
<code class="literal">md5</code>. You can pass either a hexadecimal or a
|
|||
|
|
base-32 encoding of the hash.</p></li><li class="listitem"><p>Nix can now perform builds in an automatically
|
|||
|
|
generated “chroot”. This prevents a builder from accessing stuff
|
|||
|
|
outside of the Nix store, and thus helps ensure purity. This is an
|
|||
|
|
experimental feature.</p></li><li class="listitem"><p>The new command <span class="command"><strong>nix-store
|
|||
|
|
--optimise</strong></span> reduces Nix store disk space usage by finding
|
|||
|
|
identical files in the store and hard-linking them to each other.
|
|||
|
|
It typically reduces the size of the store by something like
|
|||
|
|
25-35%.</p></li><li class="listitem"><p><code class="filename">~/.nix-defexpr</code> can now be a
|
|||
|
|
directory, in which case the Nix expressions in that directory are
|
|||
|
|
combined into an attribute set, with the file names used as the
|
|||
|
|
names of the attributes. The command <span class="command"><strong>nix-env
|
|||
|
|
--import</strong></span> (which set the
|
|||
|
|
<code class="filename">~/.nix-defexpr</code> symlink) is
|
|||
|
|
removed.</p></li><li class="listitem"><p>Derivations can specify the new special attribute
|
|||
|
|
<code class="varname">allowedReferences</code> to enforce that the references
|
|||
|
|
in the output of a derivation are a subset of a declared set of
|
|||
|
|
paths. For example, if <code class="varname">allowedReferences</code> is an
|
|||
|
|
empty list, then the output must not have any references. This is
|
|||
|
|
used in NixOS to check that generated files such as initial ramdisks
|
|||
|
|
for booting Linux don’t have any dependencies.</p></li><li class="listitem"><p>The new attribute
|
|||
|
|
<code class="varname">exportReferencesGraph</code> allows builders access to
|
|||
|
|
the references graph of their inputs. This is used in NixOS for
|
|||
|
|
tasks such as generating ISO-9660 images that contain a Nix store
|
|||
|
|
populated with the closure of certain paths.</p></li><li class="listitem"><p>Fixed-output derivations (like
|
|||
|
|
<code class="function">fetchurl</code>) can define the attribute
|
|||
|
|
<code class="varname">impureEnvVars</code> to allow external environment
|
|||
|
|
variables to be passed to builders. This is used in Nixpkgs to
|
|||
|
|
support proxy configuration, among other things.</p></li><li class="listitem"><p>Several new built-in functions:
|
|||
|
|
<code class="function">builtins.attrNames</code>,
|
|||
|
|
<code class="function">builtins.filterSource</code>,
|
|||
|
|
<code class="function">builtins.isAttrs</code>,
|
|||
|
|
<code class="function">builtins.isFunction</code>,
|
|||
|
|
<code class="function">builtins.listToAttrs</code>,
|
|||
|
|
<code class="function">builtins.stringLength</code>,
|
|||
|
|
<code class="function">builtins.sub</code>,
|
|||
|
|
<code class="function">builtins.substring</code>,
|
|||
|
|
<code class="function">throw</code>,
|
|||
|
|
<code class="function">builtins.trace</code>,
|
|||
|
|
<code class="function">builtins.readFile</code>.</p></li></ul></div></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a id="ch-relnotes-0.10.1"></a>C.26. Release 0.10.1 (2006-10-11)</h2></div></div></div><p>This release fixes two somewhat obscure bugs that occur when
|
|||
|
|
evaluating Nix expressions that are stored inside the Nix store
|
|||
|
|
(<code class="literal">NIX-67</code>). These do not affect most users.</p></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a id="ch-relnotes-0.10"></a>C.27. Release 0.10 (2006-10-06)</h2></div></div></div><div class="note"><h3 class="title">Note</h3><p>This version of Nix uses Berkeley DB 4.4 instead of 4.3.
|
|||
|
|
The database is upgraded automatically, but you should be careful not
|
|||
|
|
to use old versions of Nix that still use Berkeley DB 4.3. In
|
|||
|
|
particular, if you use a Nix installed through Nix, you should run
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-store --clear-substitutes</pre><p>
|
|||
|
|
|
|||
|
|
first.</p></div><div class="warning"><h3 class="title">Warning</h3><p>Also, the database schema has changed slighted to fix a
|
|||
|
|
performance issue (see below). When you run any Nix 0.10 command for
|
|||
|
|
the first time, the database will be upgraded automatically. This is
|
|||
|
|
irreversible.</p></div><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><p><span class="command"><strong>nix-env</strong></span> usability improvements:
|
|||
|
|
|
|||
|
|
</p><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: circle; "><li class="listitem"><p>An option <code class="option">--compare-versions</code>
|
|||
|
|
(or <code class="option">-c</code>) has been added to <span class="command"><strong>nix-env
|
|||
|
|
--query</strong></span> to allow you to compare installed versions of
|
|||
|
|
packages to available versions, or vice versa. An easy way to
|
|||
|
|
see if you are up to date with what’s in your subscribed
|
|||
|
|
channels is <code class="literal">nix-env -qc \*</code>.</p></li><li class="listitem"><p><code class="literal">nix-env --query</code> now takes as
|
|||
|
|
arguments a list of package names about which to show
|
|||
|
|
information, just like <code class="option">--install</code>, etc.: for
|
|||
|
|
example, <code class="literal">nix-env -q gcc</code>. Note that to show
|
|||
|
|
all derivations, you need to specify
|
|||
|
|
<code class="literal">\*</code>.</p></li><li class="listitem"><p><code class="literal">nix-env -i
|
|||
|
|
<em class="replaceable"><code>pkgname</code></em></code> will now install
|
|||
|
|
the highest available version of
|
|||
|
|
<em class="replaceable"><code>pkgname</code></em>, rather than installing all
|
|||
|
|
available versions (which would probably give collisions)
|
|||
|
|
(<code class="literal">NIX-31</code>).</p></li><li class="listitem"><p><code class="literal">nix-env (-i|-u) --dry-run</code> now
|
|||
|
|
shows exactly which missing paths will be built or
|
|||
|
|
substituted.</p></li><li class="listitem"><p><code class="literal">nix-env -qa --description</code>
|
|||
|
|
shows human-readable descriptions of packages, provided that
|
|||
|
|
they have a <code class="literal">meta.description</code> attribute (which
|
|||
|
|
most packages in Nixpkgs don’t have yet).</p></li></ul></div><p>
|
|||
|
|
|
|||
|
|
</p></li><li class="listitem"><p>New language features:
|
|||
|
|
|
|||
|
|
</p><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: circle; "><li class="listitem"><p>Reference scanning (which happens after each
|
|||
|
|
build) is much faster and takes a constant amount of
|
|||
|
|
memory.</p></li><li class="listitem"><p>String interpolation. Expressions like
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
"--with-freetype2-library=" + freetype + "/lib"</pre><p>
|
|||
|
|
|
|||
|
|
can now be written as
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
"--with-freetype2-library=${freetype}/lib"</pre><p>
|
|||
|
|
|
|||
|
|
You can write arbitrary expressions within
|
|||
|
|
<code class="literal">${<em class="replaceable"><code>...</code></em>}</code>, not just
|
|||
|
|
identifiers.</p></li><li class="listitem"><p>Multi-line string literals.</p></li><li class="listitem"><p>String concatenations can now involve
|
|||
|
|
derivations, as in the example <code class="code">"--with-freetype2-library="
|
|||
|
|
+ freetype + "/lib"</code>. This was not previously possible
|
|||
|
|
because we need to register that a derivation that uses such a
|
|||
|
|
string is dependent on <code class="literal">freetype</code>. The
|
|||
|
|
evaluator now properly propagates this information.
|
|||
|
|
Consequently, the subpath operator (<code class="literal">~</code>) has
|
|||
|
|
been deprecated.</p></li><li class="listitem"><p>Default values of function arguments can now
|
|||
|
|
refer to other function arguments; that is, all arguments are in
|
|||
|
|
scope in the default values
|
|||
|
|
(<code class="literal">NIX-45</code>).</p></li><li class="listitem"><p>Lots of new built-in primitives, such as
|
|||
|
|
functions for list manipulation and integer arithmetic. See the
|
|||
|
|
manual for a complete list. All primops are now available in
|
|||
|
|
the set <code class="varname">builtins</code>, allowing one to test for
|
|||
|
|
the availability of primop in a backwards-compatible
|
|||
|
|
way.</p></li><li class="listitem"><p>Real let-expressions: <code class="literal">let x = ...;
|
|||
|
|
... z = ...; in ...</code>.</p></li></ul></div><p>
|
|||
|
|
|
|||
|
|
</p></li><li class="listitem"><p>New commands <span class="command"><strong>nix-pack-closure</strong></span> and
|
|||
|
|
<span class="command"><strong>nix-unpack-closure</strong></span> than can be used to easily
|
|||
|
|
transfer a store path with all its dependencies to another machine.
|
|||
|
|
Very convenient whenever you have some package on your machine and
|
|||
|
|
you want to copy it somewhere else.</p></li><li class="listitem"><p>XML support:
|
|||
|
|
|
|||
|
|
</p><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: circle; "><li class="listitem"><p><code class="literal">nix-env -q --xml</code> prints the
|
|||
|
|
installed or available packages in an XML representation for
|
|||
|
|
easy processing by other tools.</p></li><li class="listitem"><p><code class="literal">nix-instantiate --eval-only
|
|||
|
|
--xml</code> prints an XML representation of the resulting
|
|||
|
|
term. (The new flag <code class="option">--strict</code> forces ‘deep’
|
|||
|
|
evaluation of the result, i.e., list elements and attributes are
|
|||
|
|
evaluated recursively.)</p></li><li class="listitem"><p>In Nix expressions, the primop
|
|||
|
|
<code class="function">builtins.toXML</code> converts a term to an XML
|
|||
|
|
representation. This is primarily useful for passing structured
|
|||
|
|
information to builders.</p></li></ul></div><p>
|
|||
|
|
|
|||
|
|
</p></li><li class="listitem"><p>You can now unambiguously specify which derivation to
|
|||
|
|
build or install in <span class="command"><strong>nix-env</strong></span>,
|
|||
|
|
<span class="command"><strong>nix-instantiate</strong></span> and <span class="command"><strong>nix-build</strong></span>
|
|||
|
|
using the <code class="option">--attr</code> / <code class="option">-A</code> flags, which
|
|||
|
|
takes an attribute name as argument. (Unlike symbolic package names
|
|||
|
|
such as <code class="literal">subversion-1.4.0</code>, attribute names in an
|
|||
|
|
attribute set are unique.) For instance, a quick way to perform a
|
|||
|
|
test build of a package in Nixpkgs is <code class="literal">nix-build
|
|||
|
|
pkgs/top-level/all-packages.nix -A
|
|||
|
|
<em class="replaceable"><code>foo</code></em></code>. <code class="literal">nix-env -q
|
|||
|
|
--attr</code> shows the attribute names corresponding to each
|
|||
|
|
derivation.</p></li><li class="listitem"><p>If the top-level Nix expression used by
|
|||
|
|
<span class="command"><strong>nix-env</strong></span>, <span class="command"><strong>nix-instantiate</strong></span> or
|
|||
|
|
<span class="command"><strong>nix-build</strong></span> evaluates to a function whose arguments
|
|||
|
|
all have default values, the function will be called automatically.
|
|||
|
|
Also, the new command-line switch <code class="option">--arg
|
|||
|
|
<em class="replaceable"><code>name</code></em>
|
|||
|
|
<em class="replaceable"><code>value</code></em></code> can be used to specify
|
|||
|
|
function arguments on the command line.</p></li><li class="listitem"><p><code class="literal">nix-install-package --url
|
|||
|
|
<em class="replaceable"><code>URL</code></em></code> allows a package to be
|
|||
|
|
installed directly from the given URL.</p></li><li class="listitem"><p>Nix now works behind an HTTP proxy server; just set
|
|||
|
|
the standard environment variables <code class="envar">http_proxy</code>,
|
|||
|
|
<code class="envar">https_proxy</code>, <code class="envar">ftp_proxy</code> or
|
|||
|
|
<code class="envar">all_proxy</code> appropriately. Functions such as
|
|||
|
|
<code class="function">fetchurl</code> in Nixpkgs also respect these
|
|||
|
|
variables.</p></li><li class="listitem"><p><code class="literal">nix-build -o
|
|||
|
|
<em class="replaceable"><code>symlink</code></em></code> allows the symlink to
|
|||
|
|
the build result to be named something other than
|
|||
|
|
<code class="literal">result</code>.</p></li><li class="listitem"><p>Platform support:
|
|||
|
|
|
|||
|
|
</p><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: circle; "><li class="listitem"><p>Support for 64-bit platforms, provided a <a class="link" href="http://bugzilla.sen.cwi.nl:8080/show_bug.cgi?id=606" target="_top">suitably
|
|||
|
|
patched ATerm library</a> is used. Also, files larger than 2
|
|||
|
|
GiB are now supported.</p></li><li class="listitem"><p>Added support for Cygwin (Windows,
|
|||
|
|
<code class="literal">i686-cygwin</code>), Mac OS X on Intel
|
|||
|
|
(<code class="literal">i686-darwin</code>) and Linux on PowerPC
|
|||
|
|
(<code class="literal">powerpc-linux</code>).</p></li><li class="listitem"><p>Users of SMP and multicore machines will
|
|||
|
|
appreciate that the number of builds to be performed in parallel
|
|||
|
|
can now be specified in the configuration file in the
|
|||
|
|
<code class="literal">build-max-jobs</code> setting.</p></li></ul></div><p>
|
|||
|
|
|
|||
|
|
</p></li><li class="listitem"><p>Garbage collector improvements:
|
|||
|
|
|
|||
|
|
</p><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: circle; "><li class="listitem"><p>Open files (such as running programs) are now
|
|||
|
|
used as roots of the garbage collector. This prevents programs
|
|||
|
|
that have been uninstalled from being garbage collected while
|
|||
|
|
they are still running. The script that detects these
|
|||
|
|
additional runtime roots
|
|||
|
|
(<code class="filename">find-runtime-roots.pl</code>) is inherently
|
|||
|
|
system-specific, but it should work on Linux and on all
|
|||
|
|
platforms that have the <span class="command"><strong>lsof</strong></span>
|
|||
|
|
utility.</p></li><li class="listitem"><p><code class="literal">nix-store --gc</code>
|
|||
|
|
(a.k.a. <span class="command"><strong>nix-collect-garbage</strong></span>) prints out the
|
|||
|
|
number of bytes freed on standard output. <code class="literal">nix-store
|
|||
|
|
--gc --print-dead</code> shows how many bytes would be freed
|
|||
|
|
by an actual garbage collection.</p></li><li class="listitem"><p><code class="literal">nix-collect-garbage -d</code>
|
|||
|
|
removes all old generations of <span class="emphasis"><em>all</em></span> profiles
|
|||
|
|
before calling the actual garbage collector (<code class="literal">nix-store
|
|||
|
|
--gc</code>). This is an easy way to get rid of all old
|
|||
|
|
packages in the Nix store.</p></li><li class="listitem"><p><span class="command"><strong>nix-store</strong></span> now has an
|
|||
|
|
operation <code class="option">--delete</code> to delete specific paths
|
|||
|
|
from the Nix store. It won’t delete reachable (non-garbage)
|
|||
|
|
paths unless <code class="option">--ignore-liveness</code> is
|
|||
|
|
specified.</p></li></ul></div><p>
|
|||
|
|
|
|||
|
|
</p></li><li class="listitem"><p>Berkeley DB 4.4’s process registry feature is used
|
|||
|
|
to recover from crashed Nix processes.</p></li><li class="listitem"><p>A performance issue has been fixed with the
|
|||
|
|
<code class="literal">referer</code> table, which stores the inverse of the
|
|||
|
|
<code class="literal">references</code> table (i.e., it tells you what store
|
|||
|
|
paths refer to a given path). Maintaining this table could take a
|
|||
|
|
quadratic amount of time, as well as a quadratic amount of Berkeley
|
|||
|
|
DB log file space (in particular when running the garbage collector)
|
|||
|
|
(<code class="literal">NIX-23</code>).</p></li><li class="listitem"><p>Nix now catches the <code class="literal">TERM</code> and
|
|||
|
|
<code class="literal">HUP</code> signals in addition to the
|
|||
|
|
<code class="literal">INT</code> signal. So you can now do a <code class="literal">killall
|
|||
|
|
nix-store</code> without triggering a database
|
|||
|
|
recovery.</p></li><li class="listitem"><p><span class="command"><strong>bsdiff</strong></span> updated to version
|
|||
|
|
4.3.</p></li><li class="listitem"><p>Substantial performance improvements in expression
|
|||
|
|
evaluation and <code class="literal">nix-env -qa</code>, all thanks to <a class="link" href="http://valgrind.org/" target="_top">Valgrind</a>. Memory use has
|
|||
|
|
been reduced by a factor 8 or so. Big speedup by memoisation of
|
|||
|
|
path hashing.</p></li><li class="listitem"><p>Lots of bug fixes, notably:
|
|||
|
|
|
|||
|
|
</p><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: circle; "><li class="listitem"><p>Make sure that the garbage collector can run
|
|||
|
|
successfully when the disk is full
|
|||
|
|
(<code class="literal">NIX-18</code>).</p></li><li class="listitem"><p><span class="command"><strong>nix-env</strong></span> now locks the profile
|
|||
|
|
to prevent races between concurrent <span class="command"><strong>nix-env</strong></span>
|
|||
|
|
operations on the same profile
|
|||
|
|
(<code class="literal">NIX-7</code>).</p></li><li class="listitem"><p>Removed misleading messages from
|
|||
|
|
<code class="literal">nix-env -i</code> (e.g., <code class="literal">installing
|
|||
|
|
`foo'</code> followed by <code class="literal">uninstalling
|
|||
|
|
`foo'</code>) (<code class="literal">NIX-17</code>).</p></li></ul></div><p>
|
|||
|
|
|
|||
|
|
</p></li><li class="listitem"><p>Nix source distributions are a lot smaller now since
|
|||
|
|
we no longer include a full copy of the Berkeley DB source
|
|||
|
|
distribution (but only the bits we need).</p></li><li class="listitem"><p>Header files are now installed so that external
|
|||
|
|
programs can use the Nix libraries.</p></li></ul></div></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a id="ch-relnotes-0.9.2"></a>C.28. Release 0.9.2 (2005-09-21)</h2></div></div></div><p>This bug fix release fixes two problems on Mac OS X:
|
|||
|
|
|
|||
|
|
</p><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><p>If Nix was linked against statically linked versions
|
|||
|
|
of the ATerm or Berkeley DB library, there would be dynamic link
|
|||
|
|
errors at runtime.</p></li><li class="listitem"><p><span class="command"><strong>nix-pull</strong></span> and
|
|||
|
|
<span class="command"><strong>nix-push</strong></span> intermittently failed due to race
|
|||
|
|
conditions involving pipes and child processes with error messages
|
|||
|
|
such as <code class="literal">open2: open(GLOB(0x180b2e4), >&=9) failed: Bad
|
|||
|
|
file descriptor at /nix/bin/nix-pull line 77</code> (issue
|
|||
|
|
<code class="literal">NIX-14</code>).</p></li></ul></div><p>
|
|||
|
|
|
|||
|
|
</p></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a id="ch-relnotes-0.9.1"></a>C.29. Release 0.9.1 (2005-09-20)</h2></div></div></div><p>This bug fix release addresses a problem with the ATerm library
|
|||
|
|
when the <code class="option">--with-aterm</code> flag in
|
|||
|
|
<span class="command"><strong>configure</strong></span> was <span class="emphasis"><em>not</em></span> used.</p></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a id="ch-relnotes-0.9"></a>C.30. Release 0.9 (2005-09-16)</h2></div></div></div><p>NOTE: this version of Nix uses Berkeley DB 4.3 instead of 4.2.
|
|||
|
|
The database is upgraded automatically, but you should be careful not
|
|||
|
|
to use old versions of Nix that still use Berkeley DB 4.2. In
|
|||
|
|
particular, if you use a Nix installed through Nix, you should run
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-store --clear-substitutes</pre><p>
|
|||
|
|
|
|||
|
|
first.</p><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><p>Unpacking of patch sequences is much faster now
|
|||
|
|
since we no longer do redundant unpacking and repacking of
|
|||
|
|
intermediate paths.</p></li><li class="listitem"><p>Nix now uses Berkeley DB 4.3.</p></li><li class="listitem"><p>The <code class="function">derivation</code> primitive is
|
|||
|
|
lazier. Attributes of dependent derivations can mutually refer to
|
|||
|
|
each other (as long as there are no data dependencies on the
|
|||
|
|
<code class="varname">outPath</code> and <code class="varname">drvPath</code> attributes
|
|||
|
|
computed by <code class="function">derivation</code>).</p><p>For example, the expression <code class="literal">derivation
|
|||
|
|
attrs</code> now evaluates to (essentially)
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
attrs // {
|
|||
|
|
type = "derivation";
|
|||
|
|
outPath = derivation! attrs;
|
|||
|
|
drvPath = derivation! attrs;
|
|||
|
|
}</pre><p>
|
|||
|
|
|
|||
|
|
where <code class="function">derivation!</code> is a primop that does the
|
|||
|
|
actual derivation instantiation (i.e., it does what
|
|||
|
|
<code class="function">derivation</code> used to do). The advantage is that
|
|||
|
|
it allows commands such as <span class="command"><strong>nix-env -qa</strong></span> and
|
|||
|
|
<span class="command"><strong>nix-env -i</strong></span> to be much faster since they no longer
|
|||
|
|
need to instantiate all derivations, just the
|
|||
|
|
<code class="varname">name</code> attribute.</p><p>Also, it allows derivations to cyclically reference each
|
|||
|
|
other, for example,
|
|||
|
|
|
|||
|
|
</p><pre class="programlisting">
|
|||
|
|
webServer = derivation {
|
|||
|
|
...
|
|||
|
|
hostName = "svn.cs.uu.nl";
|
|||
|
|
services = [svnService];
|
|||
|
|
};
|
|||
|
|
|
|||
|
|
svnService = derivation {
|
|||
|
|
...
|
|||
|
|
hostName = webServer.hostName;
|
|||
|
|
};</pre><p>
|
|||
|
|
|
|||
|
|
Previously, this would yield a black hole (infinite recursion).</p></li><li class="listitem"><p><span class="command"><strong>nix-build</strong></span> now defaults to using
|
|||
|
|
<code class="filename">./default.nix</code> if no Nix expression is
|
|||
|
|
specified.</p></li><li class="listitem"><p><span class="command"><strong>nix-instantiate</strong></span>, when applied to
|
|||
|
|
a Nix expression that evaluates to a function, will call the
|
|||
|
|
function automatically if all its arguments have
|
|||
|
|
defaults.</p></li><li class="listitem"><p>Nix now uses libtool to build dynamic libraries.
|
|||
|
|
This reduces the size of executables.</p></li><li class="listitem"><p>A new list concatenation operator
|
|||
|
|
<code class="literal">++</code>. For example, <code class="literal">[1 2 3] ++ [4 5
|
|||
|
|
6]</code> evaluates to <code class="literal">[1 2 3 4 5
|
|||
|
|
6]</code>.</p></li><li class="listitem"><p>Some currently undocumented primops to support
|
|||
|
|
low-level build management using Nix (i.e., using Nix as a Make
|
|||
|
|
replacement). See the commit messages for <code class="literal">r3578</code>
|
|||
|
|
and <code class="literal">r3580</code>.</p></li><li class="listitem"><p>Various bug fixes and performance
|
|||
|
|
improvements.</p></li></ul></div></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a id="ch-relnotes-0.8.1"></a>C.31. Release 0.8.1 (2005-04-13)</h2></div></div></div><p>This is a bug fix release.</p><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><p>Patch downloading was broken.</p></li><li class="listitem"><p>The garbage collector would not delete paths that
|
|||
|
|
had references from invalid (but substitutable)
|
|||
|
|
paths.</p></li></ul></div></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a id="ch-relnotes-0.8"></a>C.32. Release 0.8 (2005-04-11)</h2></div></div></div><p>NOTE: the hashing scheme in Nix 0.8 changed (as detailed below).
|
|||
|
|
As a result, <span class="command"><strong>nix-pull</strong></span> manifests and channels built
|
|||
|
|
for Nix 0.7 and below will not work anymore. However, the Nix
|
|||
|
|
expression language has not changed, so you can still build from
|
|||
|
|
source. Also, existing user environments continue to work. Nix 0.8
|
|||
|
|
will automatically upgrade the database schema of previous
|
|||
|
|
installations when it is first run.</p><p>If you get the error message
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
you have an old-style manifest `/nix/var/nix/manifests/[...]'; please
|
|||
|
|
delete it</pre><p>
|
|||
|
|
|
|||
|
|
you should delete previously downloaded manifests:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ rm /nix/var/nix/manifests/*</pre><p>
|
|||
|
|
|
|||
|
|
If <span class="command"><strong>nix-channel</strong></span> gives the error message
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
manifest `http://catamaran.labs.cs.uu.nl/dist/nix/channels/[channel]/MANIFEST'
|
|||
|
|
is too old (i.e., for Nix <= 0.7)</pre><p>
|
|||
|
|
|
|||
|
|
then you should unsubscribe from the offending channel
|
|||
|
|
(<span class="command"><strong>nix-channel --remove
|
|||
|
|
<em class="replaceable"><code>URL</code></em></strong></span>; leave out
|
|||
|
|
<code class="literal">/MANIFEST</code>), and subscribe to the same URL, with
|
|||
|
|
<code class="literal">channels</code> replaced by <code class="literal">channels-v3</code>
|
|||
|
|
(e.g., <a class="link" href="http://catamaran.labs.cs.uu.nl/dist/nix/channels-v3/nixpkgs-unstable" target="_top">http://catamaran.labs.cs.uu.nl/dist/nix/channels-v3/nixpkgs-unstable</a>).</p><p>Nix 0.8 has the following improvements:
|
|||
|
|
|
|||
|
|
</p><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><p>The cryptographic hashes used in store paths are now
|
|||
|
|
160 bits long, but encoded in base-32 so that they are still only 32
|
|||
|
|
characters long (e.g.,
|
|||
|
|
<code class="filename">/nix/store/csw87wag8bqlqk7ipllbwypb14xainap-atk-1.9.0</code>).
|
|||
|
|
(This is actually a 160 bit truncation of a SHA-256
|
|||
|
|
hash.)</p></li><li class="listitem"><p>Big cleanups and simplifications of the basic store
|
|||
|
|
semantics. The notion of “closure store expressions” is gone (and
|
|||
|
|
so is the notion of “successors”); the file system references of a
|
|||
|
|
store path are now just stored in the database.</p><p>For instance, given any store path, you can query its closure:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-store -qR $(which firefox)
|
|||
|
|
... lots of paths ...</pre><p>
|
|||
|
|
|
|||
|
|
Also, Nix now remembers for each store path the derivation that
|
|||
|
|
built it (the “deriver”):
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-store -qR $(which firefox)
|
|||
|
|
/nix/store/4b0jx7vq80l9aqcnkszxhymsf1ffa5jd-firefox-1.0.1.drv</pre><p>
|
|||
|
|
|
|||
|
|
So to see the build-time dependencies, you can do
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-store -qR $(nix-store -qd $(which firefox))</pre><p>
|
|||
|
|
|
|||
|
|
or, in a nicer format:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-store -q --tree $(nix-store -qd $(which firefox))</pre><p>
|
|||
|
|
|
|||
|
|
</p><p>File system references are also stored in reverse. For
|
|||
|
|
instance, you can query all paths that directly or indirectly use a
|
|||
|
|
certain Glibc:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-store -q --referrers-closure \
|
|||
|
|
/nix/store/8lz9yc6zgmc0vlqmn2ipcpkjlmbi51vv-glibc-2.3.4</pre><p>
|
|||
|
|
|
|||
|
|
</p></li><li class="listitem"><p>The concept of fixed-output derivations has been
|
|||
|
|
formalised. Previously, functions such as
|
|||
|
|
<code class="function">fetchurl</code> in Nixpkgs used a hack (namely,
|
|||
|
|
explicitly specifying a store path hash) to prevent changes to, say,
|
|||
|
|
the URL of the file from propagating upwards through the dependency
|
|||
|
|
graph, causing rebuilds of everything. This can now be done cleanly
|
|||
|
|
by specifying the <code class="varname">outputHash</code> and
|
|||
|
|
<code class="varname">outputHashAlgo</code> attributes. Nix itself checks
|
|||
|
|
that the content of the output has the specified hash. (This is
|
|||
|
|
important for maintaining certain invariants necessary for future
|
|||
|
|
work on secure shared stores.)</p></li><li class="listitem"><p>One-click installation :-) It is now possible to
|
|||
|
|
install any top-level component in Nixpkgs directly, through the web
|
|||
|
|
— see, e.g., <a class="link" href="http://catamaran.labs.cs.uu.nl/dist/nixpkgs-0.8/" target="_top">http://catamaran.labs.cs.uu.nl/dist/nixpkgs-0.8/</a>.
|
|||
|
|
All you have to do is associate
|
|||
|
|
<code class="filename">/nix/bin/nix-install-package</code> with the MIME type
|
|||
|
|
<code class="literal">application/nix-package</code> (or the extension
|
|||
|
|
<code class="filename">.nixpkg</code>), and clicking on a package link will
|
|||
|
|
cause it to be installed, with all appropriate dependencies. If you
|
|||
|
|
just want to install some specific application, this is easier than
|
|||
|
|
subscribing to a channel.</p></li><li class="listitem"><p><span class="command"><strong>nix-store -r
|
|||
|
|
<em class="replaceable"><code>PATHS</code></em></strong></span> now builds all the
|
|||
|
|
derivations PATHS in parallel. Previously it did them sequentially
|
|||
|
|
(though exploiting possible parallelism between subderivations).
|
|||
|
|
This is nice for build farms.</p></li><li class="listitem"><p><span class="command"><strong>nix-channel</strong></span> has new operations
|
|||
|
|
<code class="option">--list</code> and
|
|||
|
|
<code class="option">--remove</code>.</p></li><li class="listitem"><p>New ways of installing components into user
|
|||
|
|
environments:
|
|||
|
|
|
|||
|
|
</p><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: circle; "><li class="listitem"><p>Copy from another user environment:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-env -i --from-profile .../other-profile firefox</pre><p>
|
|||
|
|
|
|||
|
|
</p></li><li class="listitem"><p>Install a store derivation directly (bypassing the
|
|||
|
|
Nix expression language entirely):
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-env -i /nix/store/z58v41v21xd3...-aterm-2.3.1.drv</pre><p>
|
|||
|
|
|
|||
|
|
(This is used to implement <span class="command"><strong>nix-install-package</strong></span>,
|
|||
|
|
which is therefore immune to evolution in the Nix expression
|
|||
|
|
language.)</p></li><li class="listitem"><p>Install an already built store path directly:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-env -i /nix/store/hsyj5pbn0d9i...-aterm-2.3.1</pre><p>
|
|||
|
|
|
|||
|
|
</p></li><li class="listitem"><p>Install the result of a Nix expression specified
|
|||
|
|
as a command-line argument:
|
|||
|
|
|
|||
|
|
</p><pre class="screen">
|
|||
|
|
$ nix-env -f .../i686-linux.nix -i -E 'x: x.firefoxWrapper'</pre><p>
|
|||
|
|
|
|||
|
|
The difference with the normal installation mode is that
|
|||
|
|
<code class="option">-E</code> does not use the <code class="varname">name</code>
|
|||
|
|
attributes of derivations. Therefore, this can be used to
|
|||
|
|
disambiguate multiple derivations with the same
|
|||
|
|
name.</p></li></ul></div></li><li class="listitem"><p>A hash of the contents of a store path is now stored
|
|||
|
|
in the database after a successful build. This allows you to check
|
|||
|
|
whether store paths have been tampered with: <span class="command"><strong>nix-store
|
|||
|
|
--verify --check-contents</strong></span>.</p></li><li class="listitem"><p>Implemented a concurrent garbage collector. It is now
|
|||
|
|
always safe to run the garbage collector, even if other Nix
|
|||
|
|
operations are happening simultaneously.</p><p>However, there can still be GC races if you use
|
|||
|
|
<span class="command"><strong>nix-instantiate</strong></span> and <span class="command"><strong>nix-store
|
|||
|
|
--realise</strong></span> directly to build things. To prevent races,
|
|||
|
|
use the <code class="option">--add-root</code> flag of those commands.</p></li><li class="listitem"><p>The garbage collector now finally deletes paths in
|
|||
|
|
the right order (i.e., topologically sorted under the “references”
|
|||
|
|
relation), thus making it safe to interrupt the collector without
|
|||
|
|
risking a store that violates the closure
|
|||
|
|
invariant.</p></li><li class="listitem"><p>Likewise, the substitute mechanism now downloads
|
|||
|
|
files in the right order, thus preserving the closure invariant at
|
|||
|
|
all times.</p></li><li class="listitem"><p>The result of <span class="command"><strong>nix-build</strong></span> is now
|
|||
|
|
registered as a root of the garbage collector. If the
|
|||
|
|
<code class="filename">./result</code> link is deleted, the GC root
|
|||
|
|
disappears automatically.</p></li><li class="listitem"><p>The behaviour of the garbage collector can be changed
|
|||
|
|
globally by setting options in
|
|||
|
|
<code class="filename">/nix/etc/nix/nix.conf</code>.
|
|||
|
|
|
|||
|
|
</p><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: circle; "><li class="listitem"><p><code class="literal">gc-keep-derivations</code> specifies
|
|||
|
|
whether deriver links should be followed when searching for live
|
|||
|
|
paths.</p></li><li class="listitem"><p><code class="literal">gc-keep-outputs</code> specifies
|
|||
|
|
whether outputs of derivations should be followed when searching
|
|||
|
|
for live paths.</p></li><li class="listitem"><p><code class="literal">env-keep-derivations</code>
|
|||
|
|
specifies whether user environments should store the paths of
|
|||
|
|
derivations when they are added (thus keeping the derivations
|
|||
|
|
alive).</p></li></ul></div><p>
|
|||
|
|
|
|||
|
|
</p></li><li class="listitem"><p>New <span class="command"><strong>nix-env</strong></span> query flags
|
|||
|
|
<code class="option">--drv-path</code> and
|
|||
|
|
<code class="option">--out-path</code>.</p></li><li class="listitem"><p><span class="command"><strong>fetchurl</strong></span> allows SHA-1 and SHA-256
|
|||
|
|
in addition to MD5. Just specify the attribute
|
|||
|
|
<code class="varname">sha1</code> or <code class="varname">sha256</code> instead of
|
|||
|
|
<code class="varname">md5</code>.</p></li><li class="listitem"><p>Manual updates.</p></li></ul></div><p>
|
|||
|
|
|
|||
|
|
</p></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a id="ch-relnotes-0.7"></a>C.33. Release 0.7 (2005-01-12)</h2></div></div></div><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><p>Binary patching. When upgrading components using
|
|||
|
|
pre-built binaries (through nix-pull / nix-channel), Nix can
|
|||
|
|
automatically download and apply binary patches to already installed
|
|||
|
|
components instead of full downloads. Patching is “smart”: if there
|
|||
|
|
is a <span class="emphasis"><em>sequence</em></span> of patches to an installed
|
|||
|
|
component, Nix will use it. Patches are currently generated
|
|||
|
|
automatically between Nixpkgs (pre-)releases.</p></li><li class="listitem"><p>Simplifications to the substitute
|
|||
|
|
mechanism.</p></li><li class="listitem"><p>Nix-pull now stores downloaded manifests in
|
|||
|
|
<code class="filename">/nix/var/nix/manifests</code>.</p></li><li class="listitem"><p>Metadata on files in the Nix store is canonicalised
|
|||
|
|
after builds: the last-modified timestamp is set to 0 (00:00:00
|
|||
|
|
1/1/1970), the mode is set to 0444 or 0555 (readable and possibly
|
|||
|
|
executable by all; setuid/setgid bits are dropped), and the group is
|
|||
|
|
set to the default. This ensures that the result of a build and an
|
|||
|
|
installation through a substitute is the same; and that timestamp
|
|||
|
|
dependencies are revealed.</p></li></ul></div></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a id="ch-relnotes-0.6"></a>C.34. Release 0.6 (2004-11-14)</h2></div></div></div><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><p>Rewrite of the normalisation engine.
|
|||
|
|
|
|||
|
|
</p><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: circle; "><li class="listitem"><p>Multiple builds can now be performed in parallel
|
|||
|
|
(option <code class="option">-j</code>).</p></li><li class="listitem"><p>Distributed builds. Nix can now call a shell
|
|||
|
|
script to forward builds to Nix installations on remote
|
|||
|
|
machines, which may or may not be of the same platform
|
|||
|
|
type.</p></li><li class="listitem"><p>Option <code class="option">--fallback</code> allows
|
|||
|
|
recovery from broken substitutes.</p></li><li class="listitem"><p>Option <code class="option">--keep-going</code> causes
|
|||
|
|
building of other (unaffected) derivations to continue if one
|
|||
|
|
failed.</p></li></ul></div><p>
|
|||
|
|
|
|||
|
|
</p></li><li class="listitem"><p>Improvements to the garbage collector (i.e., it
|
|||
|
|
should actually work now).</p></li><li class="listitem"><p>Setuid Nix installations allow a Nix store to be
|
|||
|
|
shared among multiple users.</p></li><li class="listitem"><p>Substitute registration is much faster
|
|||
|
|
now.</p></li><li class="listitem"><p>A utility <span class="command"><strong>nix-build</strong></span> to build a
|
|||
|
|
Nix expression and create a symlink to the result int the current
|
|||
|
|
directory; useful for testing Nix derivations.</p></li><li class="listitem"><p>Manual updates.</p></li><li class="listitem"><p><span class="command"><strong>nix-env</strong></span> changes:
|
|||
|
|
|
|||
|
|
</p><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: circle; "><li class="listitem"><p>Derivations for other platforms are filtered out
|
|||
|
|
(which can be overridden using
|
|||
|
|
<code class="option">--system-filter</code>).</p></li><li class="listitem"><p><code class="option">--install</code> by default now
|
|||
|
|
uninstall previous derivations with the same
|
|||
|
|
name.</p></li><li class="listitem"><p><code class="option">--upgrade</code> allows upgrading to a
|
|||
|
|
specific version.</p></li><li class="listitem"><p>New operation
|
|||
|
|
<code class="option">--delete-generations</code> to remove profile
|
|||
|
|
generations (necessary for effective garbage
|
|||
|
|
collection).</p></li><li class="listitem"><p>Nicer output (sorted,
|
|||
|
|
columnised).</p></li></ul></div><p>
|
|||
|
|
|
|||
|
|
</p></li><li class="listitem"><p>More sensible verbosity levels all around (builder
|
|||
|
|
output is now shown always, unless <code class="option">-Q</code> is
|
|||
|
|
given).</p></li><li class="listitem"><p>Nix expression language changes:
|
|||
|
|
|
|||
|
|
</p><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: circle; "><li class="listitem"><p>New language construct: <code class="literal">with
|
|||
|
|
<em class="replaceable"><code>E1</code></em>;
|
|||
|
|
<em class="replaceable"><code>E2</code></em></code> brings all attributes
|
|||
|
|
defined in the attribute set <em class="replaceable"><code>E1</code></em> in
|
|||
|
|
scope in <em class="replaceable"><code>E2</code></em>.</p></li><li class="listitem"><p>Added a <code class="function">map</code>
|
|||
|
|
function.</p></li><li class="listitem"><p>Various new operators (e.g., string
|
|||
|
|
concatenation).</p></li></ul></div><p>
|
|||
|
|
|
|||
|
|
</p></li><li class="listitem"><p>Expression evaluation is much
|
|||
|
|
faster.</p></li><li class="listitem"><p>An Emacs mode for editing Nix expressions (with
|
|||
|
|
syntax highlighting and indentation) has been
|
|||
|
|
added.</p></li><li class="listitem"><p>Many bug fixes.</p></li></ul></div></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a id="ch-relnotes-0.5"></a>C.35. Release 0.5 and earlier</h2></div></div></div><p>Please refer to the Subversion commit log messages.</p></div></div></div></body></html>
|