Comment 2 for bug 1833229

Confirmed also with Mint 19.1 with latest packages, if using our internal pypi server. Creating a plain py3 virtualenv fails:

$ virtualenv testenv --python python3

Fails with:

  File "/home/user/testenv/share/python-wheels/requests-2.18.4-py2.py3-none-any.whl/requests/models.py", line 935, in raise_for_status
    raise HTTPError(http_error_msg, response=self)
requests.exceptions.HTTPError: 404 Client Error: Not Found for url: https://pypi.internal.com/simple/setuptools/

Disabling the internal pypi server from ~/.pip/pip.conf works, but of course removes access to internal packages.

Downgrading to previous version as suggested by Daniel Anderson resolved the issue:

sudo apt install python3-pip=9.0.1-2 python-pip-whl=9.0.1-2