Merge 5791bb4b3b into 27b4e2d147

headroom/cli/wrap.py

@@ -652,8 +652,23 @@ def _start_proxy(
     The caller is responsible for ensuring *port* is available
     (see ``_find_available_port``).
     """
-
-    cmd = [sys.executable, "-m", "headroom.cli", "proxy", "--port", str(port)]
+    # Keep the launching process's cwd out of the proxy's sys.path. Without
+    # this, a checkout with a top-level `headroom/` package (e.g. this repo)
+    # shadows the installed package and drops its compiled `headroom._core`
+    # extension. Python 3.11+ supports -P (PYTHONSAFEPATH); on Python 3.10,
+    # `-c` puts cwd at sys.path[0], so remove it before running the CLI module.
+    if sys.version_info >= (3, 11):
+        cmd = [sys.executable, "-P", "-m", "headroom.cli"]
+    else:
+        cmd = [
+            sys.executable,
+            "-c",
+            (
+                "import runpy, sys; sys.path.pop(0); "
+                "runpy.run_module('headroom.cli', run_name='__main__', alter_sys=True)"
+            ),
+        ]
+    cmd.extend(["proxy", "--port", str(port)])
 
     # Forward HEADROOM_MODE env var so the proxy respects the user's mode choice
     headroom_mode = os.environ.get("HEADROOM_MODE")

tests/test_cli/test_wrap_proxy_detach.py

@@ -51,6 +51,55 @@ def _capture_popen_kwargs(monkeypatch: pytest.MonkeyPatch, tmp_path: Path) -> di
     return captured
 
 
+def _capture_proxy_command(monkeypatch: pytest.MonkeyPatch, tmp_path: Path) -> list[Any]:
+    """Invoke ``_start_proxy`` with all I/O stubbed; return its command."""
+    captured: list[Any] = []
+
+    def _fake_popen(cmd: Any, **kwargs: Any) -> _FakeProc:
+        captured.clear()
+        captured.extend(cmd)
+        return _FakeProc()
+
+    monkeypatch.setattr(wrap_cli.subprocess, "Popen", _fake_popen)
+    monkeypatch.setattr(wrap_cli, "_check_proxy", lambda port: True)
+    monkeypatch.setattr(wrap_cli.time, "sleep", lambda _seconds: None)
+    monkeypatch.setattr(wrap_cli, "_get_log_path", lambda: tmp_path / "proxy.log")
+    monkeypatch.setattr(wrap_cli, "_resolve_wrap_proxy_timeout_seconds", lambda: 1)
+
+    wrap_cli._start_proxy(8787)
+    return captured
+
+
+def test_start_proxy_uses_safe_path(monkeypatch: pytest.MonkeyPatch, tmp_path: Path) -> None:
+    """The proxy subprocess must run with -P so its cwd never shadows the
+    installed package -- e.g. `headroom wrap claude` invoked from inside a
+    checkout that has its own top-level `headroom/` package would otherwise
+    import that unbuilt source tree instead, dropping `headroom._core`."""
+    monkeypatch.setattr(wrap_cli.sys, "version_info", (3, 11, 0))
+
+    captured_cmd = _capture_proxy_command(monkeypatch, tmp_path)
+
+    assert captured_cmd[0] == wrap_cli.sys.executable
+    assert captured_cmd[1] == "-P"
+
+
+def test_start_proxy_uses_compat_runner_on_python_310(
+    monkeypatch: pytest.MonkeyPatch, tmp_path: Path
+) -> None:
+    """Python 3.10 must remove cwd from sys.path without using unsupported ``-P``."""
+    monkeypatch.setattr(wrap_cli.sys, "version_info", (3, 10, 14))
+
+    captured_cmd = _capture_proxy_command(monkeypatch, tmp_path)
+
+    assert captured_cmd[:2] == [wrap_cli.sys.executable, "-c"]
+    assert "-P" not in captured_cmd
+    assert "sys.path.pop(0)" in captured_cmd[2]
+    assert (
+        "runpy.run_module('headroom.cli', run_name='__main__', alter_sys=True)" in captured_cmd[2]
+    )
+    assert captured_cmd[3:] == ["proxy", "--port", "8787"]
+
+
 def test_start_proxy_detaches_on_windows(monkeypatch: pytest.MonkeyPatch, tmp_path: Path) -> None:
     # Force the Windows branch regardless of the host OS, and supply the
     # Windows-only ``subprocess`` constants the host lacks on POSIX.