Comment 5 for bug 1834989

Thanks!

BTW I reported that the issue was with a system Qt 5.13 because although
Arch Linux updated to PyQt5 5.12.3 at the same time, I was able to
duplicate the issue with PyQt5 5.12.2 and Qt 5.13 as well -- and the
PyQt5 version has worked with calibre just fine in the past.

Fun fact: PyQt5 was already horribly broken right out of the gate, see
https://www.riverbankcomputing.com/pipermail/pyqt/2019-July/041896.html

calibre had the misfortune of being a python2-pyqt5 program rather than
a python3-pyqt5 program, so it hit this issue which made the simple act
of `python2 -c 'import PyQt5.QtCore'` do an immediate coredump.