Comment # 4 on bug 1141883 from Wolfgang Bauer

Well, it doesn't crash here on Leap 15.1 with the latest KDE packages from
additional repos.
I was able to reproduce the crash on a Tumbleweed LiveCD though, by just
running pinentry-qt and entering "BYE".

Installing Leap 15.1's pinentry-qt(5) makes the crash disappear, so the problem
actually seems to be there.
But there has been absolutely no change to it... :-/

So maybe it's caused by the switch to LTO.
I'll try to build it without, but that's just a guess.