docs: def mock_cmd(self, release, *cmd, **kwargs):
          """Run a mock command in the chroot for a given release"""
          fmt = '{mock_cmd}'
          if kwargs.get('new_chroot') is True:
              fmt +=' --new-chroot'
          fmt += ' --configdir={mock_dir}'
          return self.call(fmt.format(**release).split()
                           + list(cmd))