Bug#646215: gnome-shell doesn't seem to start

[Anthony Bourguignon]

> Is the fallback mode then started correctly?
> You should get that error message if you hardware does not support
> gnome-shell (which requires 3D and certain extensions)

I've been using gnome 3 since it has been uploaded to experimental. I'm 
using the radeon drivers which are working well.

 > What was the exact error message there?
 >
 > Do you have gnome-session and gnome-session-fallback installed? 
gnome-core?

These three packages are installed. As I said, gnome3 was working well 
since then.

The error message is this one : 
http://25.media.tumblr.com/tumblr_llb0ez6GrO1qzi8iao1_500.jpg .

 > Do you use gdm3 or any other kind of display manager?
 > Is the problem reproducible after a reboot or with a fresh user account?
 > Could you attach your ~/.xsession-errors after a failed login attempt
 > (you probably need to switch to CTRL+ALT+F1 and make a copy before you
 > login again with some other WM, as it will be overwritten).
 > Running gnome-session with "--debug" would be helpful, too. This will
 > log much more details to ~/.xsession-errors.

I'm using gdm3. The problem was reproducible after several reboots. I 
successfully restarted gnome after rollbacking the package 
gnome-session-canberra to version 0.28-2.

I'll make more tests later (upgrading the package canberra again).