cerbero: Add some debug code for figuring out random unicode errors
Sometimes vcvarsall.bat outputs data that can't be decoded as utf-8, so add some debug code for that case. For example:
https://gitlab.freedesktop.org/Hosang/gst-plugins-bad/-/jobs/4731636
https://gitlab.freedesktop.org/ocrete/gstreamer/-/jobs/4857909
Edited by Nirbheek Chauhan