Bug#838050: gnome-shell: gdm doesn't start due to a problem with gnome-shell crashing in libwacom2

[Rann Bar-On]

On Sat, 17 Sep 2016 09:37:48 +0200 Michael Biebl <biebl at debian.org>
wrote:
> Am 17.09.2016 um 01:09 schrieb Erik Tews:
> 
> > After startup, gdm doesn't show up and just shows a grey screen.
Looking at syslog reveals the reason:
> > 
> > syslog:Sep 16 23:27:25 matte kernel: [  172.983123] gnome-
shell[3206]: segfault 
> > at 10 ip 00007f8e7c85d6c4 sp 00007ffd151d0a80 error 4 in
libwacom.so.2.4.6[7f8e7
> > c85a000+9000]
> > 
> > Since I haven't updated libwacom2 in the last 2 weeks, but gnome-
shell was recently updated, I assume this is due to a problem in gnome-
shell.
> > 
> > There is also a temporary fix, just run: rmmod wacom, and then
restart gdm, and you can use it again, of course without the
touchscreen.
> > 
> > Unfortunately, in upstream, I cannot see any kind of commit between
3.21.92 and 3.21.91 that might cause such a problem.
> 
> Can you downgrade gnome-shell (and gnome-shell-common) to version
> 3.21.91-2 (from testing), reboot and test if the problem is still
> reproducible?
> 
> If not, does downgrading libmutter0i, mutter-common, mutter to
3.21.91-2
> fix the problem?
> 
> 
> -- 
> Why is it that all of the instruments seeking intelligent life in the
> universe are pointed away from Earth?
> 

Downgrading gnome-shell (and gnome-shell-common) does not help.
However, downgrading libmutter0i, mutter-common, and mutter does the
trick. Note that I also updated libwacom2 to 0.22-1, as specified in
bug 838047. On its own, that did not do the trick, but when I
downgraded the various mutter packages, the problem went away.