I am trying to build my custom distro based on impish x86_64 using debootstrap. I am not using any display drivers, only the generic ones included in linux-image-generic. I use systemd-boot as a bootloader, and I have installed gnome-session, xorg and gdm3 using apt. When I try to boot the image, everything seems to load, but when GDM3 launches, the screen goes black only with a white underscore cursor in the upper-left corner of the screen. Waiting does not solve it, it seems like GDM does not start at all. I have looked at the logs using systemctl status gdm.service, which tells me that GDM is running without any issue, and does not show me any error, failure or warning. I have then checked /var/log/gdm3, which is completely empty. Also, when I try startx, Gnome Shell instantly starts, and everything works fine from there, so that couldn't be a graphics issue.
One interesting observation is that if I boot the system, switch to a different tty, shut it down, remount and chroot the drive on the host machine and use apt -y --reinstall install gdm3, it starts working, and the GDM greeter shows up. I have tried this for like 5 rounds of rebuilding the whole thing, and it is consistently working, however, this indicates that there is an underlying problem somewhere that keeps GDM from starting on the first boot and first installation of the package.
Can someone tell me where are the log files located for gdm3, to help me troubleshoot the cause of the problem?
