Thank you, Petr, for bringing this discussion back on a solid basis, actually twice already.

And sorry for causing this problem in the first place. The "tp_print = 0" was necessary to fix misbehaviour in Py2, and we should have restricted it to Py2 back then (that line has been there since late 2013).

I think keeping some kind of a "tp_print" named field in PyTypeObject for now is the best we can do. I like Jeroen's PR (thanks for taking care of so many things at a time, Jeroen!), and I think we should just go with it.

I'm happy to release a new point release for Cython, as soon as it's clear what CPython will do, and how Cython can detect the change to adapt to it.