In the morning, shortly after a kernel upgrade (I hadn't rebooted yet),
Xorg crashed immediately after I typed Ctrl-C in an xterm (because I ran
a command with lots of output).
An excerpt of the journalctl output, though this is not much
interesting:
Jun 23 10:36:58 zira audit[369004]: ANOM_ABEND auid=1000 uid=1000 gid=1000 ses=2 subj=unconfined pid=369004 comm="emacs" exe="/usr/bin/emacs-gtk" sig=6 res=1
Jun 23 10:36:58 zira kernel: audit: type=1701 audit(1687509418.596:125): auid=1000 uid=1000 gid=1000 ses=2 subj=unconfined pid=369004 comm="emacs" exe="/usr/bin/emacs-gtk" sig=6 res=1
Jun 23 10:36:58 zira kernel: audit: type=1113 audit(1687509418.596:126): pid=1821 uid=0 auid=1000 ses=2 subj=unconfined msg='op=logout id=1000 exe="/usr/sbin/lightdm" hostname=zira addr=? terminal=/dev/tty7 res=success'
Jun 23 10:36:58 zira kernel: audit: type=1701 audit(1687509418.596:127): auid=1000 uid=1000 gid=1000 ses=2 subj=unconfined pid=13335 comm="emacs" exe="/usr/bin/emacs-gtk" sig=6 res=1
Jun 23 10:36:58 zira audit[1821]: USER_LOGOUT pid=1821 uid=0 auid=1000 ses=2 subj=unconfined msg='op=logout id=1000 exe="/usr/sbin/lightdm" hostname=zira addr=? terminal=/dev/tty7 res=success'
Jun 23 10:36:58 zira audit[13335]: ANOM_ABEND auid=1000 uid=1000 gid=1000 ses=2 subj=unconfined pid=13335 comm="emacs" exe="/usr/bin/emacs-gtk" sig=6 res=1
Jun 23 10:36:58 zira lightdm[1821]: pam_unix(lightdm:session): session closed for user vinc17
[...]
One of the emacs-gtk processes left a core dump: it aborted due to
an X related error:
[...]
#4 0x000055d0cbbb1d25 in emacs_abort () at ./debian/build-src/src/sysdep.c:2282
#5 0x000055d0cbbb0d9e in x_connection_closed (dpy=dpy@entry=0x55d0cd029910, error_message=error_message@entry=0x7ffe2320d278 "Connection lost to X server ':0'", ioerror=ioerror@entry=true) at ./debian/build-src/src/xterm.c:10218
dpyinfo = 0x55d0cd13dd60
frame = <optimized out>
tail = 0x0
idx = 5
#6 0x000055d0cbbb0e6a in x_io_error_quitter (display=0x55d0cd029910) at ./debian/build-src/src/xterm.c:10315
buf = "Connection lost to X server ':0'", '\000' <repeats 216 times>...
#7 0x00007f7c2d7d5a8f in _XIOError () at /usr/lib/x86_64-linux-gnu/libX11.so.6
#8 0x00007f7c2d7d3a1e in _XReply () at /usr/lib/x86_64-linux-gnu/libX11.so.6
#9 0x00007f7c2d7cee3b in XSync () at /usr/lib/x86_64-linux-gnu/libX11.so.6
[...]
but this seems to be just a consequence of the Xorg crash.
The machine also went into sleep, but again, this is a consequence
of the Xorg crash: I got logged out, so that my systemd-inhibit
process to prevent the sleep was no longer in effect.
Note: below, the kernel does not correspond to the running kernel
at that time (I still had 6.1.0-9-amd64).