bug#36924: fixing GDM + GNOME Shell

[Ricardo Wurmus]

Hi Guix,

Today I again couldn’t log into my workstation after upgrading the
system.  I’m using GDM + GNOME Shell.

At first GDM wouldn’t start.  I knew what to do: remove /var/lib/gdm,
because some state must have accumulated there.

GDM came up after a reboot, but I still couldn’t log in.  Instead I was
thrown back to the login screen without any error message.  I looked in
~/.cache/gdm/session.log for information, but it only told me that
gnome-shell was killed.  Thanks.

After removing both .local/share and .cache out of the way I could log
in again.

This happens whenever I upgrade the system.  This makes the system
rather frustrating to use.  I don’t know if booting into an older system
generation would result in the same problem, but my guess is that it
would because both GDM and GNOME Shell appear to be leaving some binary
files behind that cause different versions to crash unceremoneously.

What can we do to make GDM and GNOME Shell more reliable?

--
Ricardo