I am using a GStreamer overlay element with pango to render text on my video frames.

Steps to reproduce the issue:

1. launch thread, which starts GLib event loop and plays GStreamer pipeline
2. text rendering is correct
3. stop pipeline and join thread
4. launch second thread, which starts GLib event loop and plays pipeline
5. Now the text is messed up, with the following warnings:

Pango-WARNING **: 19:23:23.505: couldn't load font "serif Bold Not-Rotated 42.666015625px", falling back to "Sans Bold Not-Rotated 42.666015625px", expect ugly output.

Pango-WARNING **: 19:23:23.505: couldn't load font "Sans Bold Not-Rotated 42.666015625px", falling back to "Sans Not-Rotated 42.666015625px", expect ugly output.

Pango-WARNING **: 19:23:23.505: All font fallbacks failed!!!!

and the font is just tiny boxes.