Comment # 13 on bug 1017478 from Mark Draheim

there is not much to see in the logs. Xorg.0.log just ends with

[    64.121] (EE) 
[    64.121] (EE) Backtrace:

and then it is replaced by the new one when sddm tries again to start X.

Main journal just notes that X has died

Apr 23 12:45:37 pc7 sddm-greeter[1731]: Adding view for "LVDS-1" QRect(0,0
1920x1080)
Apr 23 12:45:37 pc7 sddm-greeter[1731]: QDBusConnection: name
'org.freedesktop.UDisks2
Apr 23 12:45:37 pc7 sddm-greeter[1731]: Message received from daemon:
Capabilities
Apr 23 12:45:37 pc7 sddm-greeter[1731]: Message received from daemon: HostName
Apr 23 12:45:37 pc7 systemd[1]: Created slice system-systemd\x2dcoredump.slice.
Apr 23 12:45:37 pc7 systemd[1]: Started Process Core Dump (PID 1765/UID 0).
Apr 23 12:45:38 pc7 sddm-greeter[1731]: The X11 connection broke: I/O error
(code 1)
Apr 23 12:45:38 pc7 sddm[1622]: Display server stopped.
Apr 23 12:45:38 pc7 sddm[1622]: Running display stop script 
"/usr/share/sddm/scripts/
Apr 23 12:45:38 pc7 sddm[1622]: Greeter stopping...
Apr 23 12:45:38 pc7 sddm[1622]: Socket server stopping...
Apr 23 12:45:38 pc7 sddm[1622]: Socket server stopped.
Apr 23 12:45:38 pc7 sddm[1622]: Removing display ":0" ...
Apr 23 12:45:38 pc7 sddm[1622]: Adding new display on vt 7 ...
Apr 23 12:45:38 pc7 sddm[1622]: Display server starting...
Apr 23 12:45:38 pc7 sddm[1622]: Running: /usr/bin/X -nolisten tcp -auth
/run/sddm/{b86
Apr 23 12:45:38 pc7 sddm-helper[1718]: [PAM] Closing session
Apr 23 12:45:38 pc7 sddm-helper[1718]: pam_unix(sddm-greeter:session): session
closed 
Apr 23 12:45:38 pc7 sddm-helper[1718]: [PAM] Ended.
Apr 23 12:45:38 pc7 systemd-logind[1600]: Removed session 1.
Apr 23 12:45:39 pc7 systemd[1]: Stopping User Manager for UID 474...
Apr 23 12:45:39 pc7 systemd[1723]: Stopping D-Bus User Message Bus...
Apr 23 12:45:39 pc7 systemd[1723]: Stopped target Default.
Apr 23 12:45:39 pc7 systemd[1723]: Stopped D-Bus User Message Bus.
Apr 23 12:45:39 pc7 systemd[1723]: Stopped target Basic System.
Apr 23 12:45:39 pc7 systemd[1723]: Stopped target Timers.
Apr 23 12:45:39 pc7 systemd[1723]: Stopped target Sockets.
Apr 23 12:45:39 pc7 systemd[1723]: Stopped target Paths.
Apr 23 12:45:39 pc7 systemd[1723]: Closed D-Bus User Message Bus Socket.
Apr 23 12:45:39 pc7 systemd[1723]: Reached target Shutdown.
Apr 23 12:45:39 pc7 systemd[1723]: Starting Exit the Session...
Apr 23 12:45:39 pc7 systemd[1723]: Received SIGRTMIN+24 from PID 1774 (kill).
Apr 23 12:45:39 pc7 systemd[1726]: pam_unix(systemd-user:session): session
closed for 
Apr 23 12:45:39 pc7 systemd[1]: Stopped User Manager for UID 474.
Apr 23 12:45:39 pc7 systemd[1]: Removed slice User Slice of sddm.
Apr 23 12:45:39 pc7 systemd-coredump[1766]: Process 1632 (X) of user 0 dumped
core.
Apr 23 12:45:39 pc7 sddm[1622]: Running display setup script 
"/etc/X11/xdm/Xsetup"
Apr 23 12:45:39 pc7 sddm[1622]: Display server started.

I see this on two computers with different Nvidia hardware and nouveau
1.0.14-2.1. The previous package 1.1 works. I also noted that the code has not
changed. Compiler or build options change?

I'd be willing to help with debugging but I do not know where to start.