imv: fix build with strictDeps = true;

[eclairevoyant]

Description of changes

Fix build with strictDeps enabled. Tracking issue: #178468

Without change, the following error occurs:

Run-time dependency cmocka found: NO (tried pkgconfig)

meson.build:209:13: ERROR: Dependency "cmocka" not found, tried pkgconfig

Result of nixpkgs-review run on x86_64-linux 1

2 packages built:

• imv
• imv.man

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/)
• 24.05 Release Notes (or backporting 23.05 and 23.11 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.

[rnhmjoj]

I don't understand this fix: pkg-config isn't a compiler, so, according to the Nixpkgs manual, whether it's in nativeBuildInputs == depsBuildHost or depsBuildBuild shouldn't matter. I checked the PATH with and without strictDeps and it's correctly added in either case.

The problem seems to be that with strictDeps the setup hook that collects the .pc files into PKG_CONFIG_PATH is not executed. I guess this is on purpose, but why?

Also, if this package is incorrect, then there are probably several thousands more: I've never seen pkg-config added to depsBuildBuild, but always to nativeBuildInputs.

[rnhmjoj]

As noted by Puna on matrix, the correct fix is to move cmocka to buildInputs: because it's a library, not a build tool.

[eclairevoyant]

Thanks, I must have misremembered that cmocka doesn't have a binary, or confused it with some other framework - I agree that it should moved to buildInputs. I do disagree with the first comment, though, in the general case.

[NickCao]

pkg-config isn't a compiler

Actually it is in some sense, pkg-config wrapper does use targetPlatform to locate .pc files of the correct platform.