nixos/nix

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Valentin Gagarin 0ea62670ed move documentation on auto-allocate-uids to options docs

this is where it belongs and can be found together with the other
options.

2022-12-01 04:40:02 +01:00

Release X.Y (202?-??-??)

<nix/fetchurl.nix> now accepts an additional argument impure which defaults to false. If it is set to true, the hash and sha256 arguments will be ignored and the resulting derivation will have __impure set to true, making it an impure derivation.
If builtins.readFile is called on a file with context, then only the parts of that context that appear in the content of the file are retained. This avoids a lot of spurious errors where some benign strings end-up having a context just because they are read from a store path (#7260).
Nix can now automatically pick UIDs for builds, removing the need to create nixbld* user accounts.

See auto-allocate-uids.
On Linux, Nix can now run builds in a user namespace where the build runs as root (UID 0) and has 65,536 UIDs available.

This is primarily useful for running containers such as systemd-nspawn inside a Nix build. For an example, see tests/systemd-nspawn/nix.

A build can enable this by by setting the derivation attribute:
```
requiredSystemFeatures = [ "uid-range" ];
```
The uid-range system feature requires the auto-allocate-uids setting to be enabled.
On Linux, Nix has experimental support for running builds inside a cgroup.

See use-cgroups.
nix build --json now prints some statistics about top-level derivations, such as CPU statistics when cgroups are enabled.