pre-commit: add rustup and gcc to support nixpkgs-fmt pre-commit-hook support

[MSchmoecker]

Description of changes

Rustup and gcc are needed in the PATH to use the nixpkgs-fmt pre-commit hook. Otherwise, pre-commit tries to install the dependencies in the pre-commit toolchain and fails:

$ pre-commit run
[INFO] Initializing environment for https://github.com/pre-commit/pre-commit-hooks.
[INFO] Initializing environment for https://github.com/psf/black.
[INFO] Initializing environment for https://github.com/pycqa/isort.
[INFO] Initializing environment for https://github.com/PyCQA/autoflake.
[INFO] Initializing environment for https://github.com/nix-community/nixpkgs-fmt.
[INFO] Installing environment for https://github.com/pre-commit/pre-commit-hooks.
[INFO] Once installed this environment will be reused.
[INFO] This may take a few minutes...
[INFO] Installing environment for https://github.com/psf/black.
[INFO] Once installed this environment will be reused.
[INFO] This may take a few minutes...
[INFO] Installing environment for https://github.com/pycqa/isort.
[INFO] Once installed this environment will be reused.
[INFO] This may take a few minutes...
[INFO] Installing environment for https://github.com/PyCQA/autoflake.
[INFO] Once installed this environment will be reused.
[INFO] This may take a few minutes...
[INFO] Installing environment for https://github.com/nix-community/nixpkgs-fmt.
[INFO] Once installed this environment will be reused.
[INFO] This may take a few minutes...
An unexpected error has occurred: CalledProcessError: command: ('/bin/sh', '/tmp/tmpukmvn9aq/rustup-init', '-y', '--quiet', '--no-modify-path', '--default-toolchain', 'none')
return code: 1
stdout: (none)
stderr:
    info: downloading installer
    Could not start dynamically linked executable: /tmp/tmp.QF1anEeoYg/rustup-init
    NixOS cannot run dynamically linked executables intended for generic
    linux environments out of the box. For more information, see:
    https://nix.dev/permalink/stub-ld
Check the log at /home/user/.cache/pre-commit/pre-commit.log

Without gcc (only rustup):

$ pre-commit run
[INFO] Installing environment for https://github.com/nix-community/nixpkgs-fmt.
[INFO] Once installed this environment will be reused.
[INFO] This may take a few minutes...
An unexpected error has occurred: CalledProcessError: command: ('/nix/store/691v6lwgyz0jhwv754c64lkk372yy1v8-rustup-1.26.0/bin/cargo', 'install', '--bins', '--root', '/home/max/.cache/pre-commit/repopsn8ksx5/rustenv-default', '--path', '.')
return code: 101
stdout: (none)
stderr:
    info: syncing channel updates for 'stable-x86_64-unknown-linux-gnu'
    info: latest update on 2024-09-05, rust version 1.81.0 (eeb90cda1 2024-09-04)
    info: downloading component 'cargo'
    info: downloading component 'clippy'
    info: downloading component 'rust-docs'
    info: downloading component 'rust-std'
    info: downloading component 'rustc'
    info: downloading component 'rustfmt'
    info: installing component 'cargo'
    info: installing component 'clippy'
    info: installing component 'rust-docs'
    info: installing component 'rust-std'
    info: installing component 'rustc'
    info: installing component 'rustfmt'
      Installing nixpkgs-fmt v1.3.0 (/home/max/.cache/pre-commit/repopsn8ksx5)
        Updating crates.io index
         Locking 63 packages to latest compatible versions
          Adding bitflags v1.3.2 (latest: v2.6.0)
          Adding cfg-if v0.1.10 (latest: v1.0.0)
          Adding clap v2.34.0 (latest: v4.5.17)
          Adding countme v2.0.4 (latest: v3.0.1)
          Adding crossbeam-channel v0.4.4 (latest: v0.5.13)
          Adding crossbeam-utils v0.7.2 (latest: v0.8.20)
          Adding hashbrown v0.9.1 (latest: v0.14.5)
          Adding hermit-abi v0.1.19 (latest: v0.4.0)
          Adding memoffset v0.6.5 (latest: v0.9.1)
          Adding rnix v0.10.2 (latest: v0.11.0)
          Adding rowan v0.12.6 (latest: v0.15.16)
          Adding rustc-hash v1.1.0 (latest: v2.0.0)
          Adding smol_str v0.1.24 (latest: v0.3.1)
          Adding strsim v0.8.0 (latest: v0.11.1)
          Adding textwrap v0.11.0 (latest: v0.16.1)
     Downloading crates ...
      Downloaded serde v1.0.209
      Downloaded serde_json v1.0.128
      Downloaded libc v0.2.158
       Compiling autocfg v1.3.0
       Compiling serde v1.0.209
       Compiling memchr v2.7.4
       Compiling crossbeam-utils v0.8.20
       Compiling libc v0.2.158
       Compiling maybe-uninit v2.0.0
       Compiling regex-syntax v0.8.4
       Compiling log v0.4.22
       Compiling hashbrown v0.9.1
       Compiling serde_json v1.0.128
       Compiling countme v2.0.4
       Compiling unicode-width v0.1.13
    error: linker `cc` not found
      |
      = note: No such file or directory (os error 2)
    
    error: could not compile `serde_json` (build script) due to 1 previous error
    warning: build failed, waiting for other jobs to finish...
    error: could not compile `serde` (build script) due to 1 previous error
    error: could not compile `maybe-uninit` (build script) due to 1 previous error
    error: could not compile `crossbeam-utils` (build script) due to 1 previous error
    error: could not compile `libc` (build script) due to 1 previous error
    error: failed to compile `nixpkgs-fmt v1.3.0 (/home/user/.cache/pre-commit/repopsn8ksx5)`, intermediate artifacts can be found at `/home/user/.cache/pre-commit/repopsn8ksx5/target`.
    To reuse those artifacts with a future compilation, set the environment variable `CARGO_TARGET_DIR` to that path.
Check the log at /home/user/.cache/pre-commit/pre-commit.log

While nixpkgs-fmt is deprecated, the replacement nixfmt does not contain pre-commit hooks in the 0.6.0 release and was just merged NixOS/nixfmt#238 on the master branch. Thus, this PR adds toolchain support for nixpkgs-fmt until nixfmt is stable.

I am not completely sure if adding the dependencies to nixpkgs is the best place, however it makes the installation of pre-commit for nix related projects much easier.

Things done

• Built on platform(s)
  • x86_64-linux
  • aarch64-linux
  • x86_64-darwin
  • aarch64-darwin
• For non-Linux: Is sandboxing enabled in nix.conf? (See Nix manual)
  • sandbox = relaxed
  • sandbox = true
• Tested, as applicable:
  • NixOS test(s) (look inside nixos/tests)
  • and/or package tests
  • or, for functions and "core" functionality, tests in lib/tests or pkgs/test
  • made sure NixOS tests are linked to the relevant packages
• Tested compilation of all packages that depend on this change using nix-shell -p nixpkgs-review --run "nixpkgs-review rev HEAD". Note: all changes have to be committed, also see nixpkgs-review usage
• Tested basic functionality of all binary files (usually in ./result/bin/)
• 24.11 Release Notes (or backporting 23.11 and 24.05 Release notes)
  • (Package updates) Added a release notes entry if the change is major or breaking
  • (Module updates) Added a release notes entry if the change is significant
  • (Module addition) Added a release notes entry if adding a new NixOS module
• Fits CONTRIBUTING.md.

---

Add a 👍 reaction to pull requests you find important.