message: coding style change from using '+' to .format().
diff: @@ -242,7 +242,7 @@ def get_temp_export_dir(timestamped_export_dir):
  """
  (dirname, basename) = os.path.split(timestamped_export_dir)
  temp_export_dir = os.path.join(
  - compat.as_bytes(dirname), compat.as_bytes('temp-' + compat.as_str(basename)))
  + compat.as_bytes(dirname), compat.as_bytes('temp-{}'.format(compat.as_str(basename))))
  return temp_export_dir
  