I've reported a bug on the KDE bugtracker with kstars-bleeding (from the unstable PPA) on ubuntu 21.04, which happen as soon as you start the application.
I've provided a backtrace, but is the KDE bugtracker the prefered way to submit a Kstars bugs ? bugs.kde.org/show_bug.cgi?id=439811
I successfully built (locally using git clone) and ran kstars on both my laptop and desktop. Perhaps the kstars-bleeding package needs to be rebuilt for AMD64 21.04...
Losmandy G11G, ZWO OAG, Celestron OAG, ASI 120MM mini guide camera, SV 80ST, TPO RC8, ASI 1600MM Pro, ASI 294MM Pro, ASI filters and filter wheel