> Bisecting confirms that this trouble started with commit

Yes, that's exactly what I thought. I don't think that [aaf11bdce2] is the cause of the bug, it only exposes a bug that must have been there already.

What more extensions does this "big wish" have? Something in it that uses fonts? Because this crash happens when cleaning up fonts, that's where I'm searching.
So far I am not able to reproduce this with a statically built wish.