Appropriate fix for msys2 bot fail on gen-def.py

[ebraminio]

Reverts the hack happened here #885 with @anthrotype help. Thanks!

[anthrotype]

I hope that doesn't break other stuff :)
it also changes the encoding of the stdout/stderr streams, so if we print anything to the console and the latter uses some weird ANSI codepage..

Maybe you should only set that env variable when calling glib-mkenums

[anthrotype]

https://ci.appveyor.com/project/harfbuzz/harfbuzz/build/1.0.1076/job/ici5gkiglm79meo6#L556

still getting UnicodeDecodeError.

Are we sure that cmake's execute_process that calls the glib-mkenums script is reading the PYTHONIOENCODING variable properly?

maybe you could try doing SET(ENV{PYTHONIOENCODING} "UTF-8") just before EXECUTE_PROCESS(...)?
https://cmake.org/pipermail/cmake/2011-August/045665.html

[ebraminio]

msys2 bot which is failing uses autotools, Behdad's territory, I fear to touch it and then get blamed :D

[behdad]

Um. No blame. :) I'll check.

[ebraminio]

Hehehe, done, lets see.

[anthrotype]

msys2 bot which is failing uses autotools

oh I see. I presume it would give the same error if one attempted to run glib-mkenums under cmake on msys2, if that env variable isn't set.

[ebraminio]

@anthrotype does it look good now? If so I think this can be merged now.