rav1e: remove build-time dependency on libgit2

[tjni]

It has a dependency on an old, vendored version of libgit2, which was causing some pain for work updating to clang 19. When investigating, we noticed that it only seems to use libgit2 at build-time to encode and later print out the commit hash as part of the version string. This can be disabled from the list of default features.

The main difference from what I can see is that the current version is printed out as:

❯ result/bin/rav1e --version
rav1e 0.7.1 () (release)
rustc 1.82.0 (f6e511eec 2024-10-15) (built from a source tarball) aarch64-apple-darwin
Compiled CPU Features: aes,crc,dit,dotprod,dpb,dpb2,fcma,fhm,flagm,fp16,frintts,jsconv,lor,lse,neon,paca,pacg,pan,pmuv3,ras,rcpc,rcpc2,rdm,sb,sha2,sha3,ssbs,vh
Runtime Assembly Support: Enabled
Runtime Assembly Level: NEON
Threading: Enabled
Unstable Features: Disabled
Compiler Flags: -Ctarget-feature=-crt-static

while afterward we have:

❯ result/bin/rav1e --version
rav1e 0.7.1 (UNKNOWN) (release)
rustc 1.82.0 (f6e511eec 2024-10-15) (built from a source tarball) aarch64-apple-darwin
Compiled CPU Features: aes,crc,dit,dotprod,dpb,dpb2,fcma,fhm,flagm,fp16,frintts,jsconv,lor,lse,neon,paca,pacg,pan,pmuv3,ras,rcpc,rcpc2,rdm,sb,sha2,sha3,ssbs,vh
Runtime Assembly Support: Enabled
Runtime Assembly Level: NEON
Threading: Enabled
Unstable Features: Disabled
Compiler Flags: -Ctarget-feature=-crt-static

Note that we don't even currently get the git revision, probably because we fetch from crate.io instead of from GitHub while keeping the .git directory intact.

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.

[paparodeo]

LGTM -- maybe target llvm-19 branch

[emilazy]

Will handle the merge myself.

[paparodeo]

Will handle the merge myself.

this triggers 1001 -> 2500 rebuilds. #355124 so shouldn't be in master.

[emilazy]

Fixed in #355456, sorry. Will reapply on llvm-19. I didn’t see any big red labels but it turns out that ofborg took over 10 hours to even get to the eval :/

[paparodeo]

Fixed in #355456, sorry. Will reapply on llvm-19. I didn’t see any big red labels but it turns out that ofborg took over 10 hours to even get to the eval :/

yeah, I could've mentioned it it my approval message

[tjni]

Sorry about that! I didn’t anticipate so many dependencies but this library is popular!

[emilazy]

I think it’s via FFmpeg, great aggregator of mass rebuilds :)