This is for investigating gitpython-developers/GitPython#1349, reproducing it and checking to see if particular changes are sufficient to solve it.
To use this without modification, the repostiory directory must be alongside the clone
of GitPython in which the changes are being made, so that they are both subdirectories
of the same directory (neither being within the other). One of the reasons this is
important is that it runs all default checks, even those that GitPython's
pyproject.toml turns off.
In addition, to get it to correctly recognize the type annoations, and also so that the
results are likely to be reliable, I did this in its own virtual environment in which I
installed GitPython non-editably by using pip install -r requirements.txt. See that
file's contents for details.
It must be uninstalled, or --upgrade passed to pip, or the virtualenv remade in
order to test it after changes, because the installation is non-editable, but this helps
better approximate the situation where GitPython is installed from PyPI.