[Impact]
Ubuntu GNOME users may install 'gnome-session-flashback' and unwittingly log into a GNOME Flashback (Compiz) session even though 'compiz' is not installed. If auto-login has not been selected the session can be changed after a hard reboot, but if auto-login has been selected it can be quite perplexing to get back to the login screen since no window manager is running and Ubuntu GNOME has no key sequence set out-of-box for killing X.
[Test Case]
Install Ubuntu GNOME Trusty selecting to automatically login during installation, apply all updates and reboot when prompted. Do not edit any key sequences. Upon reboot install only 'gnome-session-flashback', logout, then select GNOME Flashback (Compiz) and log back in. You'll find that you've logged into a session with only a blank background because no window manager is running. Attempts to kill X and return to the login screen such as restarting gdm will likely fail so you'll have to launch a TTY, manually edit "/etc/gdm/custom.conf" to turn auto-login off, and reboot in order to select a working session.
[Regression Potential]
None based on testing Ubuntu GNOME, Ubuntu, and Edubuntu Utopic with the patched files. The Edubuntu test was performed by choosing "flashback" as the default DE during installation with the Utopic 20140623 i386 image. I also tested Ubuntu GNOME both prior to and after installing 'compiz' to be sure we broke no sessions.
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Just as the title says, installing 'gnome-session-flashback' in Ubuntu GNOME provides a GNOME Flashback (Compiz) session even though 'compiz' is not installed:
lance@lance-desktop:~$ ls /usr/share/xsessions
gnome-classic.desktop gnome-fallback-compiz.desktop
gnome.desktop gnome-fallback.desktop
lance@lance-desktop:~$ apt-cache policy compiz
compiz:
Installed: (none)
Candidate: 1:0.9.11+14.04.20140423-0ubuntu1
Version table:
1:0.9.11+14.04.20140423-0ubuntu1 0
500 http://us.archive.ubuntu.com/ubuntu/ trusty-updates/main i386 Packages
1:0.9.11+14.04.20140409-0ubuntu1 0
500 http://us.archive.ubuntu.com/ubuntu/ trusty/main i386 Packages
This is much more than a minor inconvenience since Ubuntu GNOME has no keyboard shortcut set for killing X out-of-box so, if the user selected auto-login during installation, with no window manager running it can be quite difficult to get back to the login screen to select a different session.
The easiest way I found so far is to open a TTY via Ctrl+Alt+F1 and then run "sudo nano /etc/gdm/custom.conf", change "AutomaticLoginEnable=true" to "AutomaticLoginEnable=False", then run "sudo dpkg-reconfigure gdm", followed by "sudo reboot". Then on reboot a working session can be selected.
I would hope that there is some way to NOT display a session if it's window manager is not installed.
ProblemType: Bug
DistroRelease: Ubuntu 14.04
Package: gnome-session-flashback 1:3.8.0-1ubuntu12
ProcVersionSignature: Ubuntu 3.13.0-29.53-generic 3.13.11.2
Uname: Linux 3.13.0-29-generic i686
ApportVersion: 2.14.1-0ubuntu3.2
Architecture: i386
CurrentDesktop: Unity
Date: Thu Jun 19 11:27:41 2014
GsettingsChanges:
InstallationDate: Installed on 2014-05-30 (20 days ago)
InstallationMedia: Ubuntu-GNOME 14.04 LTS "Trusty Tahr" - Release i386 (20140416.2)
PackageArchitecture: all
ProcEnviron:
TERM=xterm
PATH=(custom, no user)
XDG_RUNTIME_DIR=<set>
LANG=en_US.UTF-8
SHELL=/bin/bash
SourcePackage: gnome-panel
UpgradeStatus: No upgrade log present (probably fresh install)
This bug has been reported on the Ubuntu ISO testing tracker.
A list of all reports related to this bug can be found here:
http://