Merge pull request #13299 from xokdvium/restore-packaging-overriding

flake: Restore `packaging-overriding` check

flake.nix

@@ -220,9 +220,6 @@
             This shouldn't build anything significant; just check that things
             (including derivations) are _set up_ correctly.
           */
-          # Disabled due to a bug in `testEqualContents` (see
-          # https://github.com/NixOS/nix/issues/12690).
-          /*
           packaging-overriding =
             let
               pkgs = nixpkgsFor.${system}.native;
@@ -241,7 +238,6 @@
                   # Same for all components; nix-util is an arbitrary pick
                   (nix.appendPatches [ pkgs.emptyFile ]).libs.nix-util.src;
               };
-          */
         }
         // (lib.optionalAttrs (builtins.elem system linux64BitSystems)) {
           dockerImage = self.hydraJobs.dockerImage.${system};