> I created an environment under 3.3.1 in which this error was still occurring, but within that same environment, it is not occurring for 3.7. I believe this can be closed.
Python 3.7 now uses the UTF-8 encoding when the LC_CTYPE locale is POSIX (PEP 538, PEP 540). You should still be able to reproduce the bug with a locale with an encoding different than UTF-8.
Moreover, I understand that Python 3.6 is still affected by the bug.
I don't think that we can fix this bug, sadly. But I'm happy to see that the PEP 538 and PEP 540 are already useful!