Comment 5 for bug 1878713

I think you are most likely right, but unfortunately, that didn't fix it.

unit-docker-97: 01:35:22 DEBUG unit.docker/97.upgrade-charm Processing ./wheelhouse/urllib3-1.25.8.tar.gz
unit-docker-97: 01:35:23 DEBUG unit.docker/97.upgrade-charm Complete output from command python setup.py egg_info:
unit-docker-97: 01:35:23 DEBUG unit.docker/97.upgrade-charm /usr/lib/python3.6/distutils/dist.py:261: UserWarning: Unknown distribution option: 'project_urls'
unit-docker-97: 01:35:23 DEBUG unit.docker/97.upgrade-charm warnings.warn(msg)
unit-docker-97: 01:35:23 DEBUG unit.docker/97.upgrade-charm /usr/lib/python3.6/distutils/dist.py:261: UserWarning: Unknown distribution option: 'python_requires'
unit-docker-97: 01:35:23 DEBUG unit.docker/97.upgrade-charm warnings.warn(msg)
unit-docker-97: 01:35:23 DEBUG unit.docker/97.upgrade-charm error in urllib3 setup command: 'extras_require' must be a dictionary whose values are strings or lists of strings containing valid project/version requirement specifiers.
unit-docker-97: 01:35:23 DEBUG unit.docker/97.upgrade-charm
unit-docker-97: 01:35:23 DEBUG unit.docker/97.upgrade-charm ----------------------------------------

This is where I am stuck now.