The good news is that it fixes it (although I think I might have lost lost the “DEV” reference in blue that used to show up when using a path descriptor)
The bad news for me is that because of the following changes, I have to patch further PyQt5, which I totally do not mind, but you might find you have broken a few other engines in the wild out there if __version_info__ is not defined in whatever version/flavour of PySide/PyQt is used with the PySide2Patcher class.
I will put a new version out there with the fix for tk-krita tonight and will try to check other engines when I have a the time.