pkgs/cli: Validate clan flake for clan machines list

pkgs/clan-cli/clan_cli/machines/list.py

@@ -1,7 +1,7 @@
 import argparse
 import logging
 
-from clan_lib.flake import Flake
+from clan_lib.flake import require_flake
 from clan_lib.machines.actions import list_machines
 
 from clan_cli.completions import add_dynamic_completer, complete_tags
@@ -10,7 +10,7 @@ log = logging.getLogger(__name__)
 
 
 def list_command(args: argparse.Namespace) -> None:
-    flake: Flake = args.flake
+    flake = require_flake(args.flake)
 
     for name in list_machines(flake, opts={"filter": {"tags": args.tags}}):
         print(name)

pkgs/clan-cli/clan_cli/machines/list_test.py

@@ -1,4 +1,5 @@
 import pytest
+from clan_lib.errors import ClanError
 
 from clan_cli.tests import fixtures_flakes
 from clan_cli.tests.helpers import cli
@@ -359,3 +360,12 @@ def list_mixed_tagged_untagged(
     assert "machine-with-tags" not in output.out
     assert "machine-without-tags" not in output.out
     assert output.out.strip() == ""
+
+
+def test_machines_list_require_flake_error() -> None:
+    """Test that machines list command fails when flake is required but not provided."""
+    with pytest.raises(ClanError) as exc_info:
+        cli.run(["machines", "list"])
+
+    error_message = str(exc_info.value)
+    assert "flake" in error_message.lower()