fix(local): stop re-reading cwd marker file

tests/tools/test_local_env_cwd_recovery.py

@@ -160,13 +160,14 @@ class TestUpdateCwdRejectsMissingPaths:
         with patch.object(LocalEnvironment, "init_session", autospec=True, return_value=None):
             env = LocalEnvironment(cwd=str(original), timeout=10)
 
-        # Simulate the stale-marker case: the prior command's ``pwd -P`` left
-        # a path in the cwd file, but that path has since been deleted.
+        # Simulate the stale-marker case: the prior command emitted a cwd
+        # marker for a directory that has since been deleted.
         deleted = tmp_path / "wedge-repro"
-        with open(env._cwd_file, "w") as f:
-            f.write(str(deleted))
+        marker = env._cwd_marker
 
-        env._update_cwd({"output": "", "returncode": 0})
+        env._update_cwd(
+            {"output": f"x\n{marker}{deleted}{marker}\n", "returncode": 0}
+        )
 
         assert env.cwd == str(original)
 
@@ -178,10 +179,10 @@ class TestUpdateCwdRejectsMissingPaths:
 
         with patch.object(LocalEnvironment, "init_session", autospec=True, return_value=None):
             env = LocalEnvironment(cwd=str(original), timeout=10)
+        marker = env._cwd_marker
 
-        with open(env._cwd_file, "w") as f:
-            f.write(str(new_dir))
-
-        env._update_cwd({"output": "", "returncode": 0})
+        env._update_cwd(
+            {"output": f"x\n{marker}{new_dir}{marker}\n", "returncode": 0}
+        )
 
         assert env.cwd == str(new_dir)

tests/tools/test_local_env_windows_msys.py

@@ -180,15 +180,15 @@ class TestResolveSafeCwdWindows:
 
 
 # ---------------------------------------------------------------------------
-# End-to-end: _update_cwd via marker file (Windows simulation)
+# End-to-end: _update_cwd via stdout marker (Windows simulation)
 # ---------------------------------------------------------------------------
 
 class TestUpdateCwdWindowsMsys:
-    def test_marker_file_msys_path_stored_in_native_form(
+    def test_marker_output_msys_path_stored_in_native_form(
         self, monkeypatch, tmp_path,
     ):
-        """When Git Bash writes ``/c/Users/x`` to the cwd marker file on
-        Windows, ``_update_cwd`` must translate to native form before
+        """When Git Bash emits ``/c/Users/x`` in the cwd marker on Windows,
+        ``_update_cwd`` must translate to native form before
         validating and storing — otherwise ``os.path.isdir`` rejects a
         perfectly real directory."""
         original = tmp_path / "starting"
@@ -205,18 +205,21 @@ class TestUpdateCwdWindowsMsys:
         # Pretend Git Bash wrote an MSYS path that maps to tmp_path/"next"
         new_dir = tmp_path / "next"
         new_dir.mkdir()
+        marker = env._cwd_marker
 
-        with open(env._cwd_file, "w") as f:
-            f.write("/c/whatever/from/bash")
-
-        # Translate the synthetic MSYS string to the real native dir.
+        # Translate the synthetic MSYS marker path to the real native dir.
         def fake_translate(p):
             if p == "/c/whatever/from/bash":
                 return str(new_dir)
             return p
 
         with patch.object(local_mod, "_msys_to_windows_path", side_effect=fake_translate):
-            env._update_cwd({"output": "", "returncode": 0})
+            env._update_cwd(
+                {
+                    "output": f"x\n{marker}/c/whatever/from/bash{marker}\n",
+                    "returncode": 0,
+                }
+            )
 
         assert env.cwd == str(new_dir)
 

tools/environments/local.py

@@ -1353,31 +1353,14 @@ class LocalEnvironment(BaseEnvironment):
                 pass
 
     def _update_cwd(self, result: dict):
-        """Read CWD from temp file (local-only, no round-trip needed).
+        """Update cwd from the stdout marker emitted by the wrapped command.
 
-        Skip the assignment when the path no longer exists as a directory —
-        ``pwd -P`` on a deleted cwd can leave a stale value in the marker
-        file, and propagating it would re-wedge the next ``Popen``.  The
-        ``_run_bash`` recovery path will resolve a safe fallback if needed.
-
-        On Windows, the value written by Git Bash's ``pwd -P`` is in
-        MSYS form (``/c/Users/x``). Translate it to native Windows form
-        before validating with ``os.path.isdir`` and before storing on
-        ``self.cwd``; otherwise the isdir check rejects every valid
-        result and ``_run_bash`` later prints a misleading "cwd is
-        missing" warning on every command.
+        The base command wrapper already appends ``pwd -P`` to stdout inside a
+        session-specific marker, so the local backend can share the same parser
+        as remote backends instead of re-reading the temp file it just wrote.
+        ``_extract_cwd_from_output`` keeps the local Windows normalization and
+        stale-path rollback semantics intact.
         """
-        try:
-            with open(self._cwd_file, encoding="utf-8") as f:
-                cwd_path = f.read().strip()
-            if _IS_WINDOWS:
-                cwd_path = _msys_to_windows_path(cwd_path)
-            if cwd_path and os.path.isdir(cwd_path):
-                self.cwd = cwd_path
-        except (OSError, FileNotFoundError):
-            pass
-
-        # Still strip the marker from output so it's not visible
         self._extract_cwd_from_output(result)
 
     def _extract_cwd_from_output(self, result: dict):