Yeah, the transition from ~/.xsession-errors to ~/.cache/gdm/session.log to the systemd journal wasn't really that well-executed, unfortunately.
I don't know if we have any documentation about this, either.
--Â
 Jasper
I can add this to the F19 Release Notes. However,  I don't have a box in front of me to test at the moment; does `journalctl -b -u  gdm.service` present these logs?