nixos/top-level: change extraDependencies from packages to paths

[ncfavier]

I was once again trying to work around NixOS/nix#3995 by (recursively) adding my flake inputs to system.extraDependencies; this time nixd, which depends on flake-parts, which depends on the lib subdirectory of nixpkgs.

This fails because the subdirectory flake does not pass types.package.check: it's not a derivation, and it's not a store path either (it's a subdirectory of a store path).

Change the type to path, because there's no "store path or descendant" type. Honestly I'm not sure why anyone would ever use types.package at this point.

Things done

• Built on platform(s)
  • x86_64-linux
  • aarch64-linux
  • x86_64-darwin
  • aarch64-darwin
• For non-Linux: Is sandbox = true set in nix.conf? (See Nix manual)
• 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/)
• 23.11 Release Notes (or backporting 23.05 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.

[roberth]

because there's no "store path or descendant" type.

We could call that types.pathInStore perhaps.

Honestly I'm not sure why anyone would ever use types.package at this point.

Packages and paths should be treated differently, because packages can have multiple outputs. I'm pretty sure extraDependencies doesn't treat packages like packages. What even is the implied usage for those packages? Should it keep .doc? Does that even make sense? We should probably rename it to extraPaths, so that you can guess the behavior correctly, as it effectively just takes the outPath.

[ncfavier]

Added pathInStore.

I'm not sure extraPaths is less ambiguous than extraDependencies so I've left the option name alone.

[github-actions]

Successfully created backport PR for release-23.05:

• [Backport release-23.05] nixos/top-level: change extraDependencies from packages to paths #240088