group description of data instead of spreading it across the section.
that should help direct skimming. as it turns out, people do not
actually read any of that.
this leaves open implementation details, especially about store paths
and file system objects, and allows explaining them together were it is
more appropriate. also leaves room to carefully introduce the key
insight behind Nix: applying results from programming language theory to
the operating system paradigm of files and processes.
while this may eventually introduce ugly diffs, the table will now
render readably on the terminal (e.g. for `man nix` or `nix --help`)
without further intervention.
while it appears a bit much for the overview, this way we set the stage
for going directly into data types when describing the store, instead of
first having to say what build tasks are and how they relate to build
plans.
this displays correct composition again. build inputs and build results
are not part of build plans in terms of data objects.
also this is a much less complicated setup. this will be the first
impression of architecture, and we want to get it right.
convention: describe every data type in prose, and illustrate with
a class diagram, and a textual representation of an abstract
data type.
right now we save ourselves the trouble of doing class diagrams, we can
add them later. but they are important.
use file Contents instead of Data, as that flows more naturally in the
prose.
simplify explanation of the idea behind scanning for store paths
remove references to unfinished sections.
attempt to explain used and documented terminology, as well as how
the declarative programming paradigm relates to building software.
in the future one could highlight encouraged terms to shape future
material into higher consistency.
the diagram is a first approximation and only covers that same section.
of course there is much more going on, and other features should at some
point also be illustrated.
we also have to think about presentation format and technicalities
behind it. the manual has to render to `man`, but we may want something
more refined for web view.
there should be a meta section for each chapter to give motivation of
the presented structure. the structure itself is visible from the table
of contents.
idea: sections could be read in different orders by linking them in
different ways (e.g. depth-first or breadth-first). adding hard-coded
transitions makes that confusing.
trying to capture alternative terms in one go here, mirroring everyday
use:
derivation - build plan
realise - execute build
there will be more of that sort.
The idea and most of the execution are @fricklerhandwerk's. I changed a
few things best I could based on @edolstra's corrections, and a Bazel
glossary.
Valentin Gagarin <valentin@fricklerhandwerk.de>
The current docs are all "how to do things" and no "what is Nix" or "why
are things the way they are".
I see lots of misconception on the wider internet, and I also think we
would benefit from a "living document" to answer some questions people
currently turn to the thesis for.
I think a new section of the manual can address all these issues.
it is out of date, all over the place in level of detail, is really
about `nixpkgs`, and in general instructions should not be part of
a reference manual.
also:
- update redirects and internal links
- use "Nix language" consistently
Before #5150 the copy-to-store phase of the install was idempotent,
but the recursive cp isn't. This is probably baiting a few people
into trying corrective installs that will fail.
Added using the following sed scripts:
- For command-ref/opt-common.md:
s~- `(--?)([^`]+)`~- [`\1\2`]{#opt-\2}~g
- For expressions/builtin-constants.md:
s~- `(builtins\.?)([^`]+)`~- [`\1\2`]{#builtins-\2}~g
- For expressions/advanced-attributes.md
s~^ - `([^`]+)`~ - [`\1`]{#adv-attr-\1}~g
and manually adjusted outputHashAlgo & outputHashMode.
- For glossary.md
s~^ - (`([^`]+)`|(.+)) ?\\~ - [\1]{#gloss-\2\3}\\~g;
s~(gloss-\w+) ~\1-~g
and manually adjusted anchors for Nix expression, user environment, NAR, ∅ and ε.
- For command-ref/env-common.md
s~^ - `([^`]+)`~ - [`\1`]{#env-\1}~g'
Python is only pulled into the build closure by Mercurial, which might end up being removed.
Let’s port the script to jq, which is more likely to stay.
It is now possible to use the following syntax to insert anchors into the text:
[]{#anchor-name}
The anchor will allow linking to the location it is placed by appending #anchor-name to the URL.
Additionally, it is possible to create a link pointing to its own location by adding text between the square brackets:
[`--add-root`]{#opt-add-root}
Add a new `file` fetcher type, which will fetch a plain file over
http(s), or from the local file.
Because plain `http(s)://` or `file://` urls can already correspond to
`tarball` inputs (if the path ends-up with a know archive extension),
the URL parsing logic is a bit convuluted in that:
- {http,https,file}:// urls will be interpreted as either a tarball or a
file input, depending on the extensions of the path part (so
`https://foo.com/bar` will be a `file` input and
`https://foo.com/bar.tar.gz` as a `tarball` input)
- `file+{something}://` urls will be interpreted as `file` urls (with
the `file+` part removed)
- `tarball+{something}://` urls will be interpreted as `tarball` urls (with
the `tarball+` part removed)
Fix#3785
Co-Authored-By: Tony Olagbaiye <me@fron.io>
The produced path is then allowed be imported or utilized elsewhere:
```
assert (43 == import (builtins.toFile "source" "43")); "good"
```
This will still fail on write-only stores.
Requested by ppepino on the Matrix:
https://matrix.to/#/!KqkRjyTEzAGRiZFBYT:nixos.org/$Tb32BS3rVE2BSULAX4sPm0h6CDewX2hClOTGzTC7gwM?via=nixos.org&via=matrix.org&via=nixos.dev
This adds a new command, :bl, which works like :b but also creates
a GC root symlink to the various derivation outputs.
ckie@cookiemonster ~/git/nix -> ./outputs/out/bin/nix repl
Welcome to Nix 2.6.0. Type :? for help.
nix-repl> :l <nixpkgs>
Added 16118 variables.
nix-repl> :b runCommand "hello" {} "echo hi > $out"
This derivation produced the following outputs:
./repl-result-out -> /nix/store/kidqq2acdpi05c4a9mlbg2baikmzik44-hello
[1 built, 0.0 MiB DL]
ckie@cookiemonster ~/git/nix -> cat ./repl-result-out
hi
For each `nix.conf` option, add an empty html node with a unique `id`
that can be used as an anchor target. Also make the name of the option
be a link to that target so that it’s easily discoverable.
We can’t rewrite the whole list as an html definition list like it’s
done for the builtins because these options also appear in a man page,
and the manpage renderer (lowdown) can’t render arbitrary html. But the
hack here allows to keep the manpage and have the links in the html
version.
Fix https://github.com/NixOS/nix/issues/5745
gives 2-5% performance improvement across a board of tests.
LTO is broken when using clang; some libs link fine while others crash
the linker with a segfault in the llvm linker plugin. 🙁
The uninstall instructions used to accidentally remove the nix-darwin
LaunchDaemon, this was dropped. However, the original intent was to
remove the Store volume mounting LaunchDaemon.
Clarify that `/nix` being present after the uninstall is normal and it
will only disappear after a reboot.
Co-authored-by: Travis A. Everett <travis.a.everett@gmail.com>
The multi-user installation on macOS, which is now the only option, has
gotten complicated enough that it discourages some users from checking
Nix out for fear of being left with a "dirty" system. Detailed
uninstallation instructions should make this less of an issue.
The logical implication operator is included in this section but never explained. It might stump new readers with a pretty uncommon operator, and it's never referenced explicitly.
nixpkgs can save a good bit of eval memory with this primop. zipAttrsWith is
used quite a bit around nixpkgs (eg in the form of recursiveUpdate), but the
most costly application for this primop is in the module system. it improves
the implementation of zipAttrsWith from nixpkgs by not checking an attribute
multiple times if it occurs more than once in the input list, allocates less
values and set elements, and just avoids many a temporary object in general.
nixpkgs has a more generic version of this operation, zipAttrsWithNames, but
this version is only used once so isn't suitable for being the base of a new
primop. if it were to be used more we should add a second primop instead.
This function is very useful in nixpkgs, but its implementation in Nix
itself is rather slow due to it requiring a lot of attribute set and
list appends.
Because the manual is generated from default values which are themselves
generated from various sources (cpuid, bios settings (kvm), number of
cores). This commit hides non-reproducible settings from the manual
output.
This is in line with XDG Base Directory Specification, where ~/.config is supposed to be used when XDG_CONFIG_HOME is unset.
It also better matches the reality, where ~/.config/nix.conf does not seem to be used.
- Separate the generation of the manpages from their installation
- Make sure that `make` generates the manpages
- Make sure that `make install` installs them
Fix#5051
Use a dedicated make target for the man page rather than bundling the
generation as part of `install`.
Also make sure that `make install` is a fixpoint by
- Removing the generated markdown files from `MANUAL_SRCS`
- Not having the manpage generation write in its source directory so as
to not update its timestamp (it would run each time otherwise)
This looks a lot better (and is also more semantically meaningful).
Since this list is generated in a Nix expression, I don't think using
HTML here is going to be the thing that puts people off modifying this
part of the documentation!
They are equivalent according to
<https://spec.commonmark.org/0.29/#hard-line-breaks>,
and the trailing spaces tend to be a pain (because the make git
complain, editors tend to want to remove them − the `.editorconfig`
actually specifies that − etc..).
This is already used by Hydra, and is very useful when materializing
a remote builder list from service discovery. This allows the service
discovery tool to only sync one file instead of two.
This is technically a breaking change, since attempting to set plugin
files after the first non-flag argument will now throw an error. This
is acceptable given the relative lack of stability in a plugin
interface and the need to tie the knot somewhere once plugins can
actually define new subcommands.
http://nixos.org redirects to https://nixos.org and apparently the HTTP library doesn't follow the redirect, so the output is empty.
When defining https in the request it crashes because the library doesn't seem to support https.
So this switches the example to a different http library.
As we are working towards Nix 3.0 we want to make sure that we make a
huge step forward in Nix's user experience. And once 3.0 is out of the
door we need to make sure that all future commands and features keep up
the standard of user experience.
This PR adds a CLI guideline document to the Nix documentation. Consider
this document a good starting point and a checklist when somebody will
be (re)implementing commands.
Clearly this guideline does nothing to improve user experience on its
own and can only be useful as long as it is going to be read and
cared for. But it is a first step into that direction.
Since c4c3c15c19 (#4251) building Nix for
macOS with sandboxing fails:
```
getting status of /nix/var/nix/profiles/per-user/root/channels/nixpkgs: Operation not permitted
```
This happens, because `EvalSettings::getDefaultNixPath` tries to access
paths outside the sandbox. Since the state-dir is not required for
doc generation, it is set to the dummy folder. This needs to be done
for all nix invocations during doc generation, as
`EvalSettings::getDefaultNixPath` is called unconditionally.
This removes the extra-substituters and extra-sandbox-paths settings
and instead makes every array setting extensible by setting
"extra-<name> = <value>" in the configuration file or passing
"--<name> <value>" on the command line.
pkgs.fetchurl supports an executable argument, which is especially nice
when downloading a large executable. This patch adds the same option to
nix-prefetch-url.
I have tested this to work on the simple case of prefetching a little
executable:
1. nix-prefetch-url --executable https://my/little/script
2. Paste the hash into a pkgs.fetchurl-based package, script-pkg.nix
3. Delete the output from the store to avoid any misidentified artifacts
4. Realise the package script-pkg.nix
5. Run the executable
I repeated the above while using --name, as well.
I suspect --executable would have no meaningful effect if combined with
--unpack, but I have not tried it.
Otherwise, the steps advertised in this document won't actually work
(e.g. `make install` will fail, trying to access /usr, and
`./inst/bin/nix` won't exist).
Some users have their own hashed-mirrors setup, that is used to mirror
things in addition to what’s available on tarballs.nixos.org. Although
this should be feasable to do with a Binary Cache, it’s not always
easy, since you have to remember what "name" each of the tarballs has.
Continuing to support hashed-mirrors is cheap, so it’s best to leave
support in Nix. Note that NIX_HASHED_MIRRORS is also supported in
Nixpkgs through fetchurl.nix.
Note that this excludes tarballs.nixos.org from the default, as in
\#3689. All of these are available on cache.nixos.org.
The new error-format is pretty nice from a UX point-of-view, however
it's fairly hard to parse the output e.g. for editor plugins such as
vim-ale[1] that use `nix-instantiate --parse` to determine syntax errors in
Nix expression files.
This patch extends the `internal-json` logger by adding the fields
`line`, `column` and `file` to easily locate an error in a file and the
field `raw_msg` which contains the error-message itself without
code-lines and additional helpers.
An exemplary output may look like this:
```
[nix-shell]$ ./inst/bin/nix-instantiate ~/test.nix --log-format minimal
{"action":"msg","column":1,"file":"/home/ma27/test.nix","level":0,"line":4,"raw_msg":"syntax error, unexpected IF, expecting $end","msg":"<full error-msg with code-lines etc>"}
```
[1] https://github.com/dense-analysis/ale
Nix installation now requires following redirects using `curl -L`. This
is currently represented on the [Nix download page][] but not in the
manual. This change updates the manual to reflect this.
Using `curl` without the `-L` flag results in an empty body, making
installation a no-op.
[Nix download page]: https://nixos.org/download.html
This should handle installation scenarios we can handle with
anything resembling confidence. Goal is approximating the existing
setup--not enforcing a best-practice...
Approaches (+ installer-handled, - manual) and configs each covers:
+ no change needed; /nix OK on boot volume:
All pre-Catalina (regardless of T2 or FileVault use)
+ create new unencrypted volume:
Catalina, pre-T2, no FileVault
+ create new encrypted-at-rest volume:
Catalina, pre-T2, FileVault
Catalina, T2, no FileVault
- require user to pre-create encrypted volume
Catalina, T2, FileVault
By default Nix/NixOS already set a reasonable default `max-jobs = auto`
so we don't need to mention it in this tutorial.
The option is still documented in other parts of the documentation
if users ever stumble over this.
Fixes https://github.com/NixOS/nix/issues/2531
