Comment # 2 on bug 1142448 from X Y

(In reply to Wolfgang Bauer from comment #1)
> By chance I'm currently booted into the latest Tumbleweed LiveCD (20190721),
> and QtWebEngine happens to work fine.
> 
> So this is likely caused by an incomplete upgrade or mixing incompatible
> repos/packages.

You were right, it was caused by a libfreetype6 package I still had installed
from another repo - I don't even remember why exactly.

Good catch, clear case of PEBKAC.