Unfortunately, until now I was just a happy user of Python. I suppose some day I would have to give something back, and now is as good a day as any:-), but I have studied https://docs.python.org/devguide/ for a while and it seems really scary.

It means I have to install and get acquainted with Mercurial [BTW I thought Python was on git since this year, it seems PEP 481 was just wishful thinking:(], and probably with Visual Studio since I use Windows - and I have never successfully installed that (I have some weird academic Windows licence it doesn't like, and it seems really hard to install for a single non-admin user, which is a must since this is actually not my machine:).

So, let's put the cards on the table: if the idea of your post was to initiate me in the process of becoming a good open-source citizen, then I'll bite the bullet and try to do everything in my power to actually get my equipment into a state where I can contribute to Python - but it will take time. On the other hand, if the idea was to just fix the bug in time for 3.6b1, it would be a great deal simpler if you wrote the patch. :-/