From 8ab9f61dcf787b6cbf4c2ac258621c5f4c2b18d7 Mon Sep 17 00:00:00 2001
From: fiver <fiver@example.com>
Date: Mon, 27 Apr 2026 14:17:58 +0800
Subject: [PATCH] fix(gateway): preserve WSL interop PATH in systemd units

---
 hermes_cli/gateway.py                    | 42 ++++++++++++++++++++++++
 tests/hermes_cli/test_gateway_service.py | 37 +++++++++++++++++++++
 2 files changed, 79 insertions(+)

diff --git a/hermes_cli/gateway.py b/hermes_cli/gateway.py
index dff0a4aa75..c1804f9c7f 100644
--- a/hermes_cli/gateway.py
+++ b/hermes_cli/gateway.py
@@ -1608,6 +1608,46 @@ def _build_user_local_paths(home: Path, path_entries: list[str]) -> list[str]:
     return [p for p in candidates if p not in path_entries and Path(p).exists()]
 
 
+def _build_wsl_interop_paths(path_entries: list[str]) -> list[str]:
+    """Return WSL Windows interop PATH entries for generated systemd units.
+
+    WSL shells normally inherit Windows PATH entries such as
+    ``/mnt/c/WINDOWS/System32``. systemd user services do not, so gateway tools
+    that call ``powershell.exe``/``cmd.exe`` work in a terminal but fail in the
+    background service unless we persist the relevant entries at install time.
+    """
+    if not is_wsl():
+        return []
+
+    candidates: list[str] = []
+    for entry in os.environ.get("PATH", "").split(os.pathsep):
+        if entry.startswith("/mnt/"):
+            candidates.append(entry)
+
+    for executable in ("powershell.exe", "cmd.exe", "explorer.exe", "wsl.exe"):
+        resolved = shutil.which(executable)
+        if resolved:
+            candidates.append(str(Path(resolved).parent))
+
+    for entry in (
+        "/mnt/c/WINDOWS/system32",
+        "/mnt/c/WINDOWS",
+        "/mnt/c/WINDOWS/System32/Wbem",
+        "/mnt/c/WINDOWS/System32/WindowsPowerShell/v1.0/",
+        "/mnt/c/WINDOWS/System32/OpenSSH/",
+    ):
+        if Path(entry).exists():
+            candidates.append(entry)
+
+    result: list[str] = []
+    seen = set(path_entries)
+    for entry in candidates:
+        if entry and entry not in seen:
+            seen.add(entry)
+            result.append(entry)
+    return result
+
+
 def _remap_path_for_user(path: str, target_home_dir: str) -> str:
     """Remap *path* from the current user's home to *target_home_dir*.
 
@@ -1699,6 +1739,7 @@ def generate_systemd_unit(system: bool = False, run_as_user: str | None = None)
         node_bin = _remap_path_for_user(node_bin, home_dir)
         path_entries = [_remap_path_for_user(p, home_dir) for p in path_entries]
         path_entries.extend(_build_user_local_paths(Path(home_dir), path_entries))
+        path_entries.extend(_build_wsl_interop_paths(path_entries))
         path_entries.extend(common_bin_paths)
         sane_path = ":".join(path_entries)
         return f"""[Unit]
@@ -1738,6 +1779,7 @@ WantedBy=multi-user.target
     hermes_home = str(get_hermes_home().resolve())
     profile_arg = _profile_arg(hermes_home)
     path_entries.extend(_build_user_local_paths(Path.home(), path_entries))
+    path_entries.extend(_build_wsl_interop_paths(path_entries))
     path_entries.extend(common_bin_paths)
     sane_path = ":".join(path_entries)
     return f"""[Unit]
diff --git a/tests/hermes_cli/test_gateway_service.py b/tests/hermes_cli/test_gateway_service.py
index 210c9c144e..3e9a4d3720 100644
--- a/tests/hermes_cli/test_gateway_service.py
+++ b/tests/hermes_cli/test_gateway_service.py
@@ -182,6 +182,43 @@ class TestGeneratedSystemdUnits:
 
         assert "/home/test/.nvm/versions/node/v24.14.0/bin" in unit
 
+    def test_user_unit_includes_wsl_windows_interop_paths(self, monkeypatch):
+        monkeypatch.setattr(gateway_cli, "is_wsl", lambda: True)
+        monkeypatch.setenv(
+            "PATH",
+            "/usr/local/bin:/mnt/c/WINDOWS/system32:/mnt/c/WINDOWS/System32/WindowsPowerShell/v1.0/",
+        )
+        monkeypatch.setattr(gateway_cli.shutil, "which", lambda cmd: None)
+
+        unit = gateway_cli.generate_systemd_unit(system=False)
+
+        assert "/mnt/c/WINDOWS/system32" in unit
+        assert "/mnt/c/WINDOWS/System32/WindowsPowerShell/v1.0/" in unit
+
+    def test_user_unit_omits_windows_interop_paths_outside_wsl(self, monkeypatch):
+        monkeypatch.setattr(gateway_cli, "is_wsl", lambda: False)
+        monkeypatch.setenv("PATH", "/usr/local/bin:/mnt/c/WINDOWS/system32")
+        monkeypatch.setattr(gateway_cli.shutil, "which", lambda cmd: None)
+
+        unit = gateway_cli.generate_systemd_unit(system=False)
+
+        assert "/mnt/c/WINDOWS/system32" not in unit
+
+    def test_system_unit_includes_wsl_windows_interop_paths(self, monkeypatch):
+        monkeypatch.setattr(gateway_cli, "is_wsl", lambda: True)
+        monkeypatch.setattr(
+            gateway_cli,
+            "_system_service_identity",
+            lambda run_as_user=None: ("alice", "alice", "/home/alice"),
+        )
+        monkeypatch.setattr(gateway_cli, "_hermes_home_for_target_user", lambda home: "/home/alice/.hermes")
+        monkeypatch.setenv("PATH", "/usr/local/bin:/mnt/c/WINDOWS/system32")
+        monkeypatch.setattr(gateway_cli.shutil, "which", lambda cmd: None)
+
+        unit = gateway_cli.generate_systemd_unit(system=True, run_as_user="alice")
+
+        assert "/mnt/c/WINDOWS/system32" in unit
+
     def test_system_unit_avoids_recursive_execstop_and_uses_extended_stop_timeout(self):
         unit = gateway_cli.generate_systemd_unit(system=True)