nixos-rebuild-ng: add missing FLAKE_FLAGS in nix eval calls

pkgs/by-name/ni/nixos-rebuild-ng/src/nixos_rebuild/nix.py

@@ -314,6 +314,7 @@ def get_build_image_name_flake(
     r = run_wrapper(
         [
             "nix",
+            *FLAKE_FLAGS,
             "eval",
             "--json",
             flake.to_attr(
@@ -365,6 +366,7 @@ def get_build_image_variants_flake(
     r = run_wrapper(
         [
             "nix",
+            *FLAKE_FLAGS,
             "eval",
             "--json",
             flake.to_attr("config.system.build.images"),

pkgs/by-name/ni/nixos-rebuild-ng/src/tests/test_main.py

@@ -386,6 +386,8 @@ def test_execute_nix_build_image_flake(mock_run: Mock, tmp_path: Path) -> None:
             call(
                 [
                     "nix",
+                    "--extra-experimental-features",
+                    "nix-command flakes",
                     "eval",
                     "--json",
                     '/path/to/config#nixosConfigurations."hostname".config.system.build.images',
@@ -412,6 +414,8 @@ def test_execute_nix_build_image_flake(mock_run: Mock, tmp_path: Path) -> None:
             call(
                 [
                     "nix",
+                    "--extra-experimental-features",
+                    "nix-command flakes",
                     "eval",
                     "--json",
                     '/path/to/config#nixosConfigurations."hostname".config.system.build.images.azure.passthru.filePath',

pkgs/by-name/ni/nixos-rebuild-ng/src/tests/test_nix.py

@@ -394,6 +394,8 @@ def test_get_build_image_variants_flake(mock_run: Mock) -> None:
     mock_run.assert_called_with(
         [
             "nix",
+            "--extra-experimental-features",
+            "nix-command flakes",
             "eval",
             "--json",
             "/flake.nix#myAttr.config.system.build.images",