kdenlive-22.12.0 SIGSEGV in QArrayData::data (in ThumbnailCache::storeThumbnail)

I played with kdenlive on amd64 a bit and it crashes pretty frequently
with a core indicating memory corruption. I submitted the details to the
bug tracker. If anybody has a reliable way to cause or even avoid this,
please document your findings in
https://bugs.kde.org/show_bug.cgi?id=463764

Thanks
Greg