On Windows, try harder to remove files in long_path_rmtree

asv/util.py

@@ -964,11 +964,23 @@ def long_path(path):
             return path
         return "\\\\?\\" + os.path.abspath(path)
 
-    def _remove_readonly(func, path, exc_info):
-        """Clear the readonly bit and reattempt the removal;
-        Windows rmtree doesn't do this by default"""
-        os.chmod(path, stat.S_IWRITE)
-        func(path)
+    def _remove_readonly(func, path, exc_info, wait_flag):
+        """Try harder to remove files on Windows"""
+
+        if not wait_flag[0]:
+            # Wait a bit before trying again, but only once
+            wait_flag[0] = True
+            time.sleep(1)
+
+        if exc_info[1].errno == errno.EACCES:
+            # Clear any read-only bits
+            os.chmod(path, stat.S_IRWXU | stat.S_IRWXG)
+
+        try:
+            func(path)
+        except:
+            # Reraise original error
+            six.reraise(*exc_info)
 
     def long_path_open(filename, *a, **kw):
         return open(long_path(filename), *a, **kw)
@@ -977,7 +989,8 @@ def long_path_rmtree(path, ignore_errors=False):
         if ignore_errors:
             onerror = None
         else:
-            onerror = _remove_readonly
+            wait_flag = [False]
+            onerror = lambda f, p, e: _remove_readonly(f, p, e, wait_flag)
         shutil.rmtree(long_path(path),
                       ignore_errors=ignore_errors,
                       onerror=onerror)