PkgResourcesDeprecationWarning: 0.1.36ubuntu1 is an invalid version, has anyone seen this before

This error message started to pop up for me once I've updated pip through itself. All it takes is uninstalling the initial pip version that was previously installed system-wide, which in my case, was obtained through the operating system's package manager e.g. APT.

I had a similar error upon upgrading the Ubuntu version to 20.

Removing the the python3-debian package via sudo apt-get remove --auto-remove python3-debian worked for me.

This appears to be an error in the following file: ~/.local/lib/python3.8/site-packages/pkg_resources/__init__.py

and is possibly (probably) related to the import _imp statement(s) near the top of the file.