When GNOME Shell Freezes (But You Have Unsaved Stuff There)

Mort Yao


In the past few months, I was running into the mysterious bug that GNOME Shell crashes with a segfault in libgjs.so.0.0.0, leaving me an unresponsive desktop:

  kernel: gnome-shell[963]: segfault at 7f06645fffe8 ip 00007f06d94898dd
  sp 00007fff562ee7e0 error 4 in libgjs.so.0.0.0[7f06d9

On crashing GNOME Shell does not restart itself correctly, nor gnome-shell processes are actually terminated, for some unknown reason. When this happens Mutter is completely frozen, Alt+F2 is unavailable; what’s even worse, Ctrl+Alt+F3 can’t get you a lifesaving TTY.

Clearly, the only way one can access the box then is via SSH. But what to do next? While it is possible to simply restart gdm like: (for systemd users)

$ systemctl restart gdm

This would, however, destroy the whole X session and all your open GUI processes will be lost! A desirable, more elegant approach is to restart gnome-shell alone, but this requires a few tricks in case you’re working through ssh and killall -9 gnome-shell doesn’t restart GNOME Shell properly.

  1. Login to the (borked) remote machine, and enable X11 Forwarding in its SSH daemon by modifying /etc/ssh/sshd_config, if you’ve never done it before:
    (Note that this option is not the default on most distros; you’ll have to restart sshd on the remote machine after then.)
        X11Forwarding yes
  1. Login to the remote machine again, with X11 forwarding enabled this time:
        $ ssh yourUser@yourHost -X
  1. On the borked remote machine, kill all the FUBARed gnome-shell processes, if any:
        $ pkill gnome-shell
  1. Set the correct DISPLAY environment otherwise you won’t be able to run a WM from a remote shell:
        $ export DISPLAY=:0
  1. Bring back the GNOME Shell WM, detached (so it can keep running after closing the remote shell):
        $ setsid gnome-shell

Related Gjs bug(s). The bug was there since gjs 1.48 and has been reported multiple times: #781799, #783935, #785657. Still, a recent gjs 1.49 build crashes my desktop: ( It seems rather hard to find out what would trigger the issue, but no more worries when it bumps in the night – Just get back the WM and no running window is lost.