gnome-shell broken in zesty

[Jeremy Bicha]

If you are testing Ubuntu 17.04 "zesty" (still in Alpha), do not
upgrade gnome-shell because 3.22.2-2ubuntu1 will break gdm. [1]

Since unattended-upgrades install all updates automatically [2], I
recommend you run the following commands until this issue is fixed:

sudo apt-mark hold gnome-shell
sudo apt-mark hold gnome-shell-common


Thanks,
Jeremy Bicha

[1] https://launcpad.net/bugs/1657958
[2] https://launcpad.net/bugs/1649709