'install_requires' must be a string or list of string about click-completion HOT 3 OPEN

$ python -V
Python 2.7.5
$ pip --version
pip 19.2.3 from /usr/lib/python2.7/site-packages/pip (python 2.7)

Collecting click-completion>=0.3.1 (from molecule)
  Using cached https://<internal_pypi_proxy>/repository/pypi/packages/77/fd/2d7ec2b86cd4d487abf0b13dce58e98413096c45b9645470be0cb8de6ff2/click-completion-0.5.1.tar.gz
    ERROR: Command errored out with exit status 1:
     command: /usr/bin/python2 -c 'import sys, setuptools, tokenize; sys.argv[0] = '"'"'/tmp/pip-install-TzPFb3/click-completion/setup.py'"'"'; __file__='"'"'/tmp/pip-install-TzPFb3/click-completion/setup.py'"'"';f=getattr(tokenize, '"'"'open'"'"', open)(__file__);code=f.read().replace('"'"'\r\n'"'"', '"'"'\n'"'"');f.close();exec(compile(code, __file__, '"'"'exec'"'"'))' egg_info --egg-base pip-egg-info
         cwd: /tmp/pip-install-TzPFb3/click-completion/
    Complete output (1 lines):
    error in click-completion setup command: 'install_requires' must be a string or list of strings containing valid project/version requirement specifiers
    ----------------------------------------
ERROR: Command errored out with exit status 1: python setup.py egg_info Check the logs for full command output.

$ python -V
Python 2.7.5
$ pip --version
pip 19.3.1 from /usr/lib/python2.7/site-packages/pip (python 2.7)
$ pip list | grep setuptools
setuptools                       42.0.2