What is your development environment to develop gdm?

Hi,

how do you launch gdm in “development mode”?

Do you have a trick to launch it manually?
Or even in “development mode” you launch gdm with systemd, e.g. a systemctl restart gdm?

Context: I would like to try to work on this https://gitlab.gnome.org/GNOME/gdm/-/issues/462

Best regards,
Stéphane