• Index the tree for references. If .git exists, use ls-tree equivalent

• Check the validity of the pkgs/unit directory, https://github.com/nixpkgs-architecture/rfcs/blob/master/rfcs/0140-simple-package-paths.md#detailed-design

  • Structure: Check not needed, we can check that in Nix
  • Only derivations
  • Stable boundary: Shouldn't reference files outside, neither be referenced from outside
  • Custom arguments: all-packages.nix can reference unit directories in a limited way

• Loop through all definitions in all-packages.nix

  • If the definition could be migrated:
    • If --mode=migrate, migrate the code, output a message
    • If --mode=warn, output a warning message only
      • If in GitHub Actions, create a code annotation
    • If --mode=error, output an error message, fail at the end
      • If in GitHub Actions, create a code annotation

Perhaps create code annotations only when they're in a file that's changed by the PR