Comment # 4 on bug 1003809 from Dominique Leuenberger

Interesting part from the log:

Oct 13 15:10:54 linux-p3ar kernel: traps: gnome-shell[5079] trap invalid opcode
ip:7f2dd471308f sp:7ffc58f0d460 error:0traps: 
Oct 13 15:10:54 linux-p3ar systemd-coredump[4309]: Process 4224 (gnome-shell)
of user 478 dumped core.

so there should be coredump around.

Please try to extract a stack trace using:
coredumctl gdb gnome-shell

at the prompt, type "thread apply all bt full"

If it tells you about missing packages, follow the instructions and install
them, then repeat extractnig the backtrace (as long as there a ??? in the
trace, it is incomplete)