Hello Alex Andreotti, just tried to reproduce this issue but did not happen inside my unstable amd64 qemu VM.
Probably you can install an core dump collector like systemd-coredump? Then you could see the stack where the crash happened by: coredumpctl gdb list coredumpctl gdb <PID> And even better would be if you could add the debug symbol repository described in [1] and install e.g. lightdm-gtk-greeter-dbgsym plus maybe more dbgsym packages for the shared objects shown in the stack. Kind regards, Bernhard [1] https://wiki.debian.org/HowToGetABacktrace
