@property
  def tag_name(self):
    # Calls to git describe can have bad performance on large repos.  Be aware
    # of the performance hit if you use this property.
    tag = self._check_output(['describe', '--tags', '--always'], raise_type=Scm.LocalException)
    return None if tag in b'cannot' else tag
dataset/ETHPy150Open pantsbuild/pants/src/python/pants/scm/git.py/Git.tag_name/swapped operands of `in`