fix rmtree
diff --git a/buildkite/pipelines/bazelci.py b/buildkite/pipelines/bazelci.py
index 3f1847e..34fb04b 100644
--- a/buildkite/pipelines/bazelci.py
+++ b/buildkite/pipelines/bazelci.py
@@ -47,7 +47,7 @@
             delete_repository(git_repository)
     finally:
         if tmpdir:
-             os.rmtree(tmpdir)
+             shutil.rmtree(tmpdir)
         cleanup(bazel_binary)
         exit(exit_code)