python312Packages.protobuf: propagate pkgs.protobuf

[GaetanLepage]

Things done

Previously to the latest staging-next merge, python3Packages.protobuf was pointing to python-modules/protobuf/4.nix.
This derivation, apart from building the python bindings for protobuf from source, does propagate the actual pkgs/protobuf package which provides the downstream dependents with the protoc binary.

Now, the current python3Packages.protobuf package is a new derivation which does not propagate pkgs.protobuf.
Hence, several packages that rely on protoc now fail to build.

This PR reintroduces this propagation of pkgs.protobuf.

• 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.

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[SomeoneSerge]

RE: Splicing

Unless there's even more magic that I know not of, I think splicing doesn't work this way yet:

But maybe that's what @Artturin's #349316 would change?

[SomeoneSerge]

[Artturin]

RE: Splicing

Unless there's even more magic that I know not of, I think splicing doesn't work this way yet:

But maybe that's what @Artturin's #349316 would change?

That's normal, derivations inside derivations aren't spliced

[SomeoneSerge]

Not my interpretation: the argument passed via newScope here is spliced, and the argument passed in overrides isn't

[vcunat]

Sounds good to me. Feel free to keep improving :-)