docs: def as_cwd():
      """ Use workdir.options.path as a temporary working directory """
      _set_log_level()
      owd = os.getcwd()
      logger.debug('entering working directory: ' + options.path)
      os.chdir(os.path.expanduser(options.path))
      yield
      logger.debug('returning to original directory: ' + owd)
      os.chdir(owd)