pkgconfig: rename to pkg-config

[zimbatm]

Package attrs should map to the pname. It's confusing otherwise.

pkg-config is also the name used by most distributions:

Debian, Homebrew, Guix, OpenSuse

other distributions like FreeBSD ports, Fedora and Arch Linux call it
"pkgconf"

Waiting a few releases to make a tree-wide change to make it easier to
back-port things.

Motivation for this change

I keep typing pkg-config all the time.

Things done

• Tested using sandboxing (nix.useSandbox on NixOS, or option sandbox in nix.conf on non-NixOS)
• Built on platform(s)
  • NixOS
  • macOS
  • other Linux distributions
• Tested via one or more NixOS test(s) if existing and applicable for the change (look inside nixos/tests)
• Tested compilation of all pkgs that depend on this change using nix-shell -p nox --run "nox-review wip"
• Tested execution of all binary files (usually in ./result/bin/)
• Determined the impact on package closure size (by running nix path-info -S before and after)
• Assured whether relevant documentation is up to date
• Fits CONTRIBUTING.md.

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[matthewbauer]

Looks good! This might be one to not put in aliases.nix for a while since it is almost everywhere.

[zimbatm]

Ok, glad to see that I am not alone :) There are more packages that don't map 1:1 with their pname by the way.

I think you are right, since pkg-config is used in the bootstrap, evaluation fails if it's in in the aliases.nix.

[jtojnar]

Hmm, repology displays the same name for nixpkgs: https://repology.org/metapackage/pkg-config/versions

Also a side note: pkgconf is a competing project that implements pkg-config command for compatibility.

[vcunat]

👍 for alias, one way or another. I think adding aliases is safe even for the stable branch, easing backports. I'm not really certain a mass replace is worth it, but this PR isn't really about that.

[vcunat]

Repology displays the "name" attribute, not the attribute name, so that's already "pkg-config". (uh, how would I better formulate that :)

[zimbatm]

Evaluation fails if I move it into aliases.nix, probably because it's an input for the stdenv and aliases.nix only comes after the stdenv bootstrap.