PIP3 | WARNING: Could not generate requirement for distribution -ertifi 2019.11.28

I got into similar problem after I have upgraded my pip under windows from version 20.1.1 to version 20.2.3

It turned out that old version of pip was renaming folders that it could not delete, replacing first letter with tilda ~

The new version of pip counts this tilda as hyphen - I don't know why