ci/eval/compare: handle missing packages (#439198)

  anyMatchingFiles = files: builtins.any anyMatchingFile files;

  attrsWithMaintainers = builtins.map (

  attrsWithMaintainers = lib.pipe (changedattrs ++ removedattrs) [

    (builtins.map (

      name:

      let

      package = lib.getAttrFromPath (lib.splitString "." name) pkgs;

        # Some packages might be reported as changed on a different platform, but

        # not even have an attribute on the platform the maintainers are requested on.

        # Fallback to `null` for these to filter them out below.

        package = lib.attrByPath (lib.splitString "." name) null pkgs;

      in

      {

        inherit name package;

        # Note that this will require keeping track of GH team IDs in "maintainers/teams.nix".

        maintainers = package.meta.maintainers or [ ];

      }

  ) (changedattrs ++ removedattrs);

    ))

    # No need to match up packages without maintainers with their files.

    # This also filters out attributes where `packge = null`, which is the

    # case for libintl, for example.

    (builtins.filter (pkg: pkg.maintainers != [ ]))

  ];

  relevantFilenames =

    drv: