When sandbox-fallback = true (the default), the Nix builder will fall
back to disabled sandbox mode when the kernel doesn’t allow users to
set it up. This prevents hard errors from occuring in tricky places,
especially the initial installer. To restore the previous behavior,
users can set:
sandbox-fallback = false
in their /etc/nix/nix.conf configuration.
This flag
* Disables substituters.
* Sets the tarball-ttl to infinity (ensuring e.g. that the flake
registry and any downloaded flakes are considered current).
* Disables retrying downloads and sets the connection timeout to the
minimum. (So it doesn't completely disable downloads at the moment.)
(cherry picked from commit 8ea842260b)
Allow global config settings to be defined in multiple Config
classes. For example, this means that libutil can have settings and
evaluator settings can be moved out of libstore. The Config classes
are registered in a new GlobalConfig class to which config files
etc. are applied.
Relevant to https://github.com/NixOS/nix/issues/2009 in that it
removes the need for ad hoc handling of useCaseHack, which was the
underlying cause of that issue.
This allows specifying additional systems that a machine is able to
build for. This may apply on some armv7-capable aarch64 processors, or
on systems using qemu-user with binfmt-misc to support transparent
execution of foreign-arch programs.
This removes the previous hard-coded assumptions about which systems are
ABI-compatible with which other systems, and instead relies on the user
to specify any additional platforms that they have ensured compatibility
for and wish to build for locally.
NixOS should probably add i686-linux on x86_64-linux systems for this
setting by default.
The overhead of sandbox builds is a problem on NixOS (since building a
NixOS configuration involves a lot of small derivations) but not for
typical non-NixOS use cases. So outside of NixOS we can enable it.
Issue #179.
Previously, this would fail at startup for non-NixOS installs:
nix-env --help
The fix for this is to just use "nixManDir" as the value for MANPATH
when spawning "man".
To test this, I’m using the following:
$ nix-build release.nix -A build
$ MANPATH= ./result/bin/nix-env --help
Fixes#1627
In this mode, the following restrictions apply:
* The builtins currentTime, currentSystem and storePath throw an
error.
* $NIX_PATH and -I are ignored.
* fetchGit and fetchMercurial require a revision hash.
* fetchurl and fetchTarball require a sha256 attribute.
* No file system access is allowed outside of the paths returned by
fetch{Git,Mercurial,url,Tarball}. Thus 'nix build -f ./foo.nix' is
not allowed.
Thus, the evaluation result is completely reproducible from the
command line arguments. E.g.
nix build --pure-eval '(
let
nix = fetchGit { url = https://github.com/NixOS/nixpkgs.git; rev = "9c927de4b179a6dd210dd88d34bda8af4b575680"; };
nixpkgs = fetchGit { url = https://github.com/NixOS/nixpkgs.git; ref = "release-17.09"; rev = "66b4de79e3841530e6d9c6baf98702aa1f7124e4"; };
in (import (nix + "/release.nix") { inherit nix nixpkgs; }).build.x86_64-linux
)'
The goal is to enable completely reproducible and traceable
evaluation. For example, a NixOS configuration could be fully
described by a single Git commit hash. 'nixos-rebuild' would do
something like
nix build --pure-eval '(
(import (fetchGit { url = file:///my-nixos-config; rev = "..."; })).system
')
where the Git repository /my-nixos-config would use further fetchGit
calls or Git externals to fetch Nixpkgs and whatever other
dependencies it has. Either way, the commit hash would uniquely
identify the NixOS configuration and allow it to reproduced.
The name had become a misnomer since it's not only for substitution
from binary caches, but when adding/copying any
(non-content-addressed) path to a store.
You can now include files via the "builders" option, using the syntax
"@<filename>". Having only one option makes it easier to override
builders completely.
For backward compatibility, the default is "@/etc/nix/machines", or
"@<filename>" for each file name in NIX_REMOTE_SYSTEMS.
I needed this to test ACL/xattr removal in
canonicalisePathMetaData(). Might also be useful if you need to build
old Nixpkgs that doesn't have the required patches to remove
setuid/setgid creation.
Nix can now automatically run the garbage collector during builds or
while adding paths to the store. The option "min-free = <bytes>"
specifies that Nix should run the garbage collector whenever free
space in the Nix store drops below <bytes>. It will then delete
garbage until "max-free" bytes are available.
Garbage collection during builds is asynchronous; running builds are
not paused and new builds are not blocked. However, there also is a
synchronous GC run prior to the first build/substitution.
Currently, no old GC roots are deleted (as in "nix-collect-garbage
-d").
In particular, drop the "build-" and "gc-" prefixes which are
pointless. So now you can say
nix build --no-sandbox
instead of
nix build --no-build-use-sandbox
This allows builds to call setuid binaries. This was previously
possible until we started using seccomp. Turns out that seccomp by
default disallows processes from acquiring new privileges. Generally,
any use of setuid binaries (except those created by the builder
itself) is by definition impure, but some people were relying on this
ability for certain tests.
Example:
$ nix build '(with import <nixpkgs> {}; runCommand "foo" {} "/run/wrappers/bin/ping -c 1 8.8.8.8; exit 1")' --no-allow-new-privileges
builder for ‘/nix/store/j0nd8kv85hd6r4kxgnwzvr0k65ykf6fv-foo.drv’ failed with exit code 1; last 2 log lines:
cannot raise the capability into the Ambient set
: Operation not permitted
$ nix build '(with import <nixpkgs> {}; runCommand "foo" {} "/run/wrappers/bin/ping -c 1 8.8.8.8; exit 1")' --allow-new-privileges
builder for ‘/nix/store/j0nd8kv85hd6r4kxgnwzvr0k65ykf6fv-foo.drv’ failed with exit code 1; last 6 log lines:
PING 8.8.8.8 (8.8.8.8) 56(84) bytes of data.
64 bytes from 8.8.8.8: icmp_seq=1 ttl=46 time=15.2 ms
Fixes#1429.
This is useful for one-off situations where you want to specify a
builder on the command line instead of having to mess with
nix.machines. E.g.
$ nix-build -A hello --argstr system x86_64-darwin \
--option builders 'root@macstadium1 x86_64-darwin'
will perform the specified build on "macstadium1".
It also removes the need for a separate nix.machines file since you
can specify builders in nix.conf directly. (In fact nix.machines is
yet another hack that predates the general nix.conf configuration
file, IIRC.)
Note: this option is supported by the daemon for trusted users. The
fact that this allows trusted users to specify paths to SSH keys to
which they don't normally have access is maybe a bit too much trust...
This is to simplify remote build configuration. These environment
variables predate nix.conf.
The build hook now has a sensible default (namely build-remote).
The current load is kept in the Nix state directory now.
Linus Heckemann