Fix hud debug dockerfile.hud error

hud/cli/__init__.py

@@ -194,9 +194,9 @@ def debug(
 
     from .utils.environment import (
         build_environment,
+        find_dockerfile,
         get_image_name,
         image_exists,
-        is_environment_directory,
     )
 
     hud_console = HUDConsole()
@@ -224,8 +224,9 @@ def debug(
         first_param = params[0]
         docker_args = params[1:] if len(params) > 1 else []
 
-        # Check if it's a directory
-        if Path(first_param).exists() and is_environment_directory(first_param):
+        # Check if it's a directory with a Dockerfile
+        p = Path(first_param)
+        if p.exists() and p.is_dir() and find_dockerfile(p) is not None:
             # Directory mode - like hud dev
             directory = first_param
 

hud/cli/tests/test_debug_directory_mode.py

@@ -0,0 +1,33 @@
+from __future__ import annotations
+
+from typing import TYPE_CHECKING
+
+if TYPE_CHECKING:
+    from pathlib import Path
+
+
+def test_hud_debug_directory_mode_accepts_dockerfile_hud_without_pyproject(
+    tmp_path: Path, monkeypatch
+) -> None:
+    """Test that hud debug . works with Dockerfile.hud and no pyproject.toml."""
+    (tmp_path / "Dockerfile.hud").write_text("FROM python:3.11\n", encoding="utf-8")
+    monkeypatch.chdir(tmp_path)
+
+    import hud.cli.__init__ as cli
+    from hud.cli.utils import environment as env_utils
+
+    monkeypatch.setattr(env_utils, "image_exists", lambda _image: True)
+
+    captured: dict[str, object] = {}
+
+    async def _fake_debug_mcp_stdio(command, logger, max_phase: int = 5) -> int:  # type: ignore[no-untyped-def]
+        captured["command"] = command
+        return max_phase
+
+    monkeypatch.setattr(cli, "debug_mcp_stdio", _fake_debug_mcp_stdio)
+    cli.debug(params=["."], config=None, cursor=None, build=False, max_phase=1)
+
+    command = captured["command"]
+    assert isinstance(command, list)
+    expected_name = tmp_path.name.replace("_", "-")
+    assert command[-1] == f"{expected_name}:dev"

hud/cli/utils/environment.py

@@ -78,12 +78,22 @@ def build_environment(directory: str | Path, image_name: str, no_cache: bool = F
     Returns:
         True if build succeeded, False otherwise
     """
+    dir_path = Path(directory)
+    dockerfile_path = find_dockerfile(dir_path)
+
     build_cmd = ["docker", "build", "-t", image_name]
+
+    # Specify the Dockerfile path if using Dockerfile.hud
+    if dockerfile_path is not None and dockerfile_path.name != "Dockerfile":
+        build_cmd.extend(["-f", str(dockerfile_path)])
+
     if no_cache:
         build_cmd.append("--no-cache")
     build_cmd.append(str(directory))
 
     hud_console.info(f"🔨 Building image: {image_name}{' (no cache)' if no_cache else ''}")
+    if dockerfile_path is not None and dockerfile_path.name != "Dockerfile":
+        hud_console.info(f"Using {dockerfile_path.name}")
     hud_console.info("")  # Empty line before Docker output
 
     # Just run Docker build directly - it has its own nice live display
@@ -110,20 +120,33 @@ def image_exists(image_name: str) -> bool:
     return result.returncode == 0
 
 
+def find_dockerfile(directory: Path) -> Path | None:
+    """Find Dockerfile in a directory, preferring Dockerfile.hud over Dockerfile."""
+    hud_dockerfile = directory / "Dockerfile.hud"
+    if hud_dockerfile.exists():
+        return hud_dockerfile
+
+    standard_dockerfile = directory / "Dockerfile"
+    if standard_dockerfile.exists():
+        return standard_dockerfile
+
+    return None
+
+
 def is_environment_directory(path: str | Path) -> bool:
     """Check if a path looks like an environment directory.
 
     An environment directory should have:
-    - A Dockerfile
+    - A Dockerfile (Dockerfile.hud or Dockerfile)
     - A pyproject.toml file
     - Optionally a src directory
     """
     dir_path = Path(path)
     if not dir_path.is_dir():
         return False
 
-    # Must have Dockerfile
-    if not (dir_path / "Dockerfile").exists():
+    # Must have Dockerfile.hud or Dockerfile
+    if find_dockerfile(dir_path) is None:
         return False
 
     # Must have pyproject.toml

hud/cli/utils/tests/test_environment.py

@@ -3,7 +3,12 @@
 from typing import TYPE_CHECKING
 from unittest.mock import MagicMock, patch
 
-from hud.cli.utils.environment import get_image_name, image_exists, is_environment_directory
+from hud.cli.utils.environment import (
+    find_dockerfile,
+    get_image_name,
+    image_exists,
+    is_environment_directory,
+)
 
 if TYPE_CHECKING:
     from pathlib import Path
@@ -36,6 +41,40 @@ def test_is_environment_directory(tmp_path: Path):
     assert is_environment_directory(d) is True
 
 
+def test_is_environment_directory_with_dockerfile_hud(tmp_path: Path):
+    """Test that Dockerfile.hud is recognized as a valid environment directory."""
+    d = tmp_path / "env"
+    d.mkdir()
+    assert is_environment_directory(d) is False
+    # Use Dockerfile.hud instead of Dockerfile
+    (d / "Dockerfile.hud").write_text("FROM python:3.11")
+    assert is_environment_directory(d) is False
+    (d / "pyproject.toml").write_text("[tool.hud]")
+    assert is_environment_directory(d) is True
+
+
+def test_find_dockerfile_prefers_dockerfile_hud(tmp_path: Path):
+    """Test that Dockerfile.hud is preferred over Dockerfile."""
+    d = tmp_path / "env"
+    d.mkdir()
+    # No Dockerfile
+    assert find_dockerfile(d) is None
+    # Add Dockerfile
+    (d / "Dockerfile").write_text("FROM python:3.11")
+    assert find_dockerfile(d) == d / "Dockerfile"
+    # Add Dockerfile.hud - should now be preferred
+    (d / "Dockerfile.hud").write_text("FROM python:3.12")
+    assert find_dockerfile(d) == d / "Dockerfile.hud"
+
+
+def test_find_dockerfile_only_dockerfile_hud(tmp_path: Path):
+    """Test that Dockerfile.hud alone is found."""
+    d = tmp_path / "env"
+    d.mkdir()
+    (d / "Dockerfile.hud").write_text("FROM python:3.11")
+    assert find_dockerfile(d) == d / "Dockerfile.hud"
+
+
 @patch("subprocess.run")
 def test_image_exists_true(mock_run):
     mock_run.return_value = MagicMock(returncode=0)