GDM does not work if gnome-session is not installed

[Jeremy Bícha]

Test Case
=========
Install Ubuntu 17.10 from a recent daily image.
After install log in.
sudo apt install gdm3
Choose gdm3 when prompted.
Restart your computer.

The bug is that gdm refuses to start

Workaround
==========
Install gnome-session

More Info
=========
For smoother upgrades and to allow the option of a more vanilla GNOME experience, it was decided to try to continue to use an ubuntu-session package by default containing an "ubuntu" session that identifies as "Ubuntu" and runs GNOME. We don't want or need the GNOME sessions in the default install.

This is more fallout from https://git.gnome.org/browse/gdm/commit/?id=f66cdfcb so let's try reverting that change.

See also LP: #1686257 and https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=850291

[Launchpad Janitor (janitor)]

This bug was fixed in the package gdm3 - 3.24.2-1ubuntu3

---------------
gdm3 (3.24.2-1ubuntu3) artful; urgency=medium

  * debian/control.in: Update Vcs field
  * Add revert_drop_gdm_shell_session.patch:
    - Revert commit that requires gnome-session to be installed
      (LP: #1701243, Closes: #850291)
  * debian/gdm3.install:
    - Install gnome-session file

 -- Jeremy Bicha <email address hidden> Thu, 29 Jun 2017 10:44:24 -0400