Remove the lock file before releasing it.

compyle/ext_module.py

@@ -163,9 +163,9 @@ def _lock(self, timeout=90):
         try:
             yield
         finally:
-            self.lck.release()
             if exists(self.lock_path):
                 os.remove(self.lock_path)
+            self.lck.release()
 
     def _write_source(self, path):
         if not exists(path):