Index: utils/lit/lit/TestRunner.py
===================================================================
--- utils/lit/lit/TestRunner.py
+++ utils/lit/lit/TestRunner.py
@@ -607,7 +607,19 @@
                 if not recursive:
                     stderr.write("Error: %s is a directory\n" % path)
                     exitCode = 1
-                shutil.rmtree(path, onerror = on_rm_error if force else None)
+                if platform.system() == 'Windows':
+                    # NOTE: use ctypes to access `RemoveDirectoryW` on Windows
+                    # to use the NT style path to get access to long file paths
+                    # which cannot be removed otherwise.  On python 2.7,
+                    # `shutil.rmtree` is backed by `RemoveDirectoryA` which does
+                    # not support the NT style path, so we must resort to the
+                    # ctypes import.
+                    import ctypes
+                    path = os.path.abspath(path)
+                    if not ctypes.windll.kernel32.RemoveDirectoryW(r'\\?\%s' % path):
+                        raise ctypes.WinError()
+                else:
+                    shutil.rmtree(path, onerror = on_rm_error if force else None)
             else:
                 if force and not os.access(path, os.W_OK):
                     os.chmod(path,