I'm getting this error when attempting to build my Python / Flask app on Heroku (was deploying just fine a few days ago):
Cannot uninstall 'certifi'. It is a distutils installed project and thus we cannot accurately determine which files belong to it which would lead to only a partial uninstall. You are using pip version 10.0.1, however version 18.0 is available.
I've tried to correct this by upgrading pip version, but it doesn't seem to stick. Every time the build is initiated, I see it's still loading pip version 10.
I have a requirements.txt as part of the app, but pip isn't listed in there.