Merge pull request #259318 from K900/fix-externally-defined-nixos-tests

            {

              virtualisation.qemu.package = testModuleArgs.config.qemu.package;

            })

          (optionalAttrs (!config.node.pkgsReadOnly) {

          ({ options, ... }: {

            key = "nodes.nix-pkgs";

            config = {

            config = mkIf (!options.nixpkgs.pkgs.isDefined) {

              # Ensure we do not use aliases. Ideally this is only set

              # when the test framework is used by Nixpkgs NixOS tests.

              nixpkgs.config.allowAliases = false;