gnome-shell crashed with SIGSEGV in clutter_stage_view_get_onscreen() from meta_stage_impl_add_onscreen_frame_info() from add_onscreen_frame_info() from post_finish_frame() from try_post_latest_swap()

Looks like triple buffering, probably.

If there is anything I can do to assist in getting this bug fixed, please let me know. Today I had two crashes on resume from the lock screen.

Me too. From lock screen, I unlocked with password and turned on my monitor. 2 seconds later it crashed.

I haven't been able to reproduce this crash yet, but it looks like it's related to monitors disconnecting during sleep mode (which is normal but doesn't happen on all machines). So I will have to try more types of monitors...

I'm using a ThinkPad T14 (AMD) Gen 1 connected to a 38" LG monitor via USB-C using DisplayPort alternate mode. I can quite reliably reproduce the crash, it happens a few times per day when resuming from a locked screen.

Fixed, I think...

https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1441/diffs?commit_id=07385bf3091080fc9711a5de6160d4ebc2d406bf

This bug was fixed in the package mutter - 44.2-3ubuntu1

---------------
mutter (44.2-3ubuntu1) mantic; urgency=medium

  * Merge with Debian. Remaining changes:
    - Add x11-Add-support-for-fractional-scaling-using-Randr.patch
    - Add window-Add-ability-to-override-the-edge-constraints.patch
      + Make possible for extensions (such as Tiling Assistant) to override
        window constraints

mutter (44.2-3) experimental; urgency=medium

  * Cherry-pick patch to fix build test with mesa 23.1 (LP: #2025287)

mutter (44.2-2ubuntu1) mantic; urgency=medium

  * Merge with Debian. Remaining changes:
    - Add x11-Add-support-for-fractional-scaling-using-Randr.patch
    - Add window-Add-ability-to-override-the-edge-constraints.patch
      + Make possible for extensions (such as Tiling Assistant) to override
        window constraints

mutter (44.2-2) experimental; urgency=medium

  [ Daniel van Vugt ]
  * Cherry-pick 2 patches for stuttering fixes
    * Avoid cursor stuttering over some windows (LP: #2023766). This will also
      improve best-case input latency by roughly half a frame.
    * Avoid render stuttering in some fullscreen games (LP: #2016990).
  * Update Support-Dynamic-triple-double-buffering.patch
    * Fix a failure to resume from sleep (frozen black screen), which seems
      to be an old bug but only became likely in 44.1.
    * Fix a crash on resume from sleep (LP: #2020049).

 -- Jeremy Bícha <email address hidden> Wed, 28 Jun 2023 15:31:07 -0400

Is there a way to test the fix with Ubuntu Lunar?

It's in proposed:
https://launchpad.net/ubuntu/+source/mutter/44.3-0ubuntu1

I upgraded to mutter to 44.3-0ubuntu1 but am still experiencing crashes after resume from lock screen.

Log output:

Jul 17 16:13:59 ThinkPad-T14-flb kernel: gnome-shell[4048]: segfault at ffffffffffffff48 ip 00007f9efa316ebb sp 00007ffd043ed2d8 error 5 in libmutter-clutter-12.so.0.0.0[7f9efa2b4000+8b000] likely on CPU 14 (core 7, socket 0)
Jul 17 16:13:59 ThinkPad-T14-flb kernel: Code: 30 48 85 c0 74 09 c3 0f 1f 84 00 00 00 00 00 48 8b 47 68 48 85 c0 75 ee 48 8b 47 28 c3 66 90 f3 0f 1e fa 48 63 05 b5 e7 07 00 <48> 8b 44 38 28 c3 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 f3

Please let me know if and how I can assist in further debugging.

Florian, please report a new bug by following:
https://wiki.ubuntu.com/Bugs/Responses#Missing_a_crash_report_or_having_a_.crash_attachment

I tried reporting my most recent crash but ubuntu-bug just exits immediately when I try to send the report with 'ubuntu-bug <crashfile>' and pressing S afterwards. I'll continue trying to report it.

Try using 'apport-cli' instead of 'ubuntu-bug'.

If crash reports still get rejected then check that all your packages are up to date before reporting another:

  sudo apt update
  sudo apt full-upgrade