Apply suggestions from code review

Co-authored-by: Robert Hensing <roberth@users.noreply.github.com>

tests/nixos/default.nix

@@ -21,7 +21,8 @@ let
       defaults = {
         nixpkgs.pkgs = nixpkgsFor.${system}.native;
         nix.checkAllErrors = false;
-        nix.package = noTests nixpkgsFor.${system}.native.nixComponents.nix-cli;
+        # TODO: decide which packaging stage to use. `nix-cli` is efficient, but not the same as the user-facing `everything.nix` package (`default`). Perhaps a good compromise is `everything.nix` + `noTests` defined above?
+        nix.package = nixpkgsFor.${system}.native.nixComponents.nix-cli;
       };
       _module.args.nixpkgs = nixpkgs;
       _module.args.system = system;
@@ -36,7 +37,9 @@ let
           # NOTE: noTests pkg might not have been built yet for some older versions of the package
           #       and in versions before 2.25, the untested build wasn't shared with the tested build yet
           #       Add noTests here when those versions become irrelevant.
-          nix = (builtins.getFlake "nix/${nixVersion}").packages.${system}.nix-cli;
+          nix = let
+            packages = builtins.getFlake "nix/${nixVersion}").packages.${system};
+          in packages.nix-cli or packages.nix;
         })];
       };
     };