fix(core): enable Windows support with msvcrt file locking and POSIX tree keys (fixes #151)

harness2/core/schedule.py

@@ -286,16 +286,39 @@ def _load_old(path: Path) -> dict:
         return {}
 
 
+def _lock_summary(lf) -> None:
+    """Exclusive lock on the summary lock file (flock on POSIX, msvcrt on Windows)."""
+    if os.name == "nt":
+        import msvcrt
+
+        lf.seek(0)
+        msvcrt.locking(lf.fileno(), msvcrt.LK_LOCK, 1)
+    else:
+        import fcntl
+
+        fcntl.flock(lf, fcntl.LOCK_EX)
+
+
+def _unlock_summary(lf) -> None:
+    if os.name == "nt":
+        import msvcrt
+
+        lf.seek(0)
+        msvcrt.locking(lf.fileno(), msvcrt.LK_UNLCK, 1)
+    else:
+        import fcntl
+
+        fcntl.flock(lf, fcntl.LOCK_UN)
+
+
 def _write_summary(summary_path: Path, res: TaskResult) -> None:
     """Merge `res` into the summary under an flock, atomically, deriving the merged status.
 
     Modes may be written by separate processes, so records accumulate per mode.
     """
-    import fcntl
-
     lock = summary_path.with_suffix(".lock")
     with open(lock, "w") as lf:
-        fcntl.flock(lf, fcntl.LOCK_EX)
+        _lock_summary(lf)
         try:
             merged = res.to_dict()
             if summary_path.is_file():
@@ -325,7 +348,7 @@ def _write_summary(summary_path: Path, res: TaskResult) -> None:
             tmp.write_text(json.dumps(merged, indent=2, default=str))
             os.replace(tmp, summary_path)
         finally:
-            fcntl.flock(lf, fcntl.LOCK_UN)
+            _unlock_summary(lf)
 
 
 def _resolve_libraries(

harness2/core/tree.py

@@ -137,7 +137,7 @@ def read_tree(surface: SurfaceSpec, d: Path | str, *, rejected: list[str] | None
     for p in sorted(d.rglob("*")):
         if not p.is_file() or "__pycache__" in p.parts:
             continue
-        rel = str(p.relative_to(d))
+        rel = normalize_rel(str(p.relative_to(d)))
         if rel in stubs:
             continue
         if not is_allowed(surface, rel):
@@ -164,7 +164,7 @@ def write_tree(surface: SurfaceSpec, tree: Tree, dest: Path | str, *, stubs: boo
     for p in sorted(dest.rglob("*"), reverse=True):
         if not p.is_file():
             continue
-        rel = str(p.relative_to(dest))
+        rel = normalize_rel(str(p.relative_to(dest)))
         if is_allowed(surface, rel) or rel in stub_set:
             p.unlink()
     for a in surface.always_on: