pip will change the way that it resolves dependency conflicts after october 2020

[palmoreck]

After October 2020 you may experience errors when installing or updating packages. This is because pip will change the way that it resolves dependency conflicts.

We recommend you use --use-feature=2020-resolver to test your packages with the new resolver before it becomes the default.

Check:

https://stackoverflow.com/questions/63277123/what-is-use-feature-2020-resolver-error-message-with-jupyter-installation-on

https://pip.pypa.io/en/latest/user_guide/#changes-to-the-pip-dependency-resolver-in-20-2-2020