(In reply to Stephan van den Akker from comment #11) > Now I don't get warnings any more when I uninstall libproj12. Progress! > > But still QGIS will not start up properly when libproj12 is installed. > > Apparently libproj12 gets precedence over libproj13 when it's installed in > parallel and therefore still manages to crash QGIS. Is there anything preventing uninstalling libproj12? I am asking as I would like to know if some more packages need rebuild triggered. Anyways I will try to solve this conflict as well.