Metacity crash corrupts future Gnome sessions

[Luc Stroobant]

To trigger the bug easily:
- open the session capplet, activate automatic session saving on logout
- open an emacs windows (or anything else not handling session saving correctly)
- close your GNOME session
- open a new one

There is no window manager started

[Sebastien Bacher (seb128)]

Thank you for your bug. Need retracing on amd64

[Haggai Eran (haggai-eran)]

Hi
I think I have a similar bug. metacity doesn't start automatically when I log in. I believe it started after I tried to use Desktop Effects.

Regards,
Haggai Eran

[DLCBurggraaff (burdi)]

My "administrative" user experienced the same symptoms after upgrading the 80 packages that were updated since Apr 11.
Invoking the "Windows" Preferences gave a popup "Cannot start the preferences application for your window manager", "Window manager "unknown" has not registered a configuration tool.
Removing the ~/.gnome2 directory made the symptoms disappear.

Root did not experience the problem.

[Luc Stroobant (ubuntu-stroobant)]

Attached the crash report found on the other system, which is running a 32-bit Ubuntu. Might be usefull too?

[Luc Stroobant (ubuntu-stroobant)]

Today my system crashed again and I made a screenshot to illustrate the problem (attached). I also have a new metacity crash report dated at the moment of my previou shutdown. I'll upload it if it's usefull to analyse a third one.

I can confirm now that everything works fine again after removing just $HOME/.gnome2/session (so you don't need to remove the complete .gnome2 directory).

[Thomas Meire (blackskad)]

I can confirm this bug on a 32-bit system. I'm seeing this problem since my upgrade to feisty last Thursday (so most likely, this bug is feisty only). However, metacity doesn't always crash at shutdown. I've found a crash report from Friday (at 2.42 am), but the last time I've shut my laptop down was Friday around 22.30 pm, which implies that metacity didn't crash at 22.30pm.
My work around: try to click the terminal icon before it gets covered, and then execute gnome-wm from the terminal. This brings metacity back on - without the need to remove the .gnome2/session file.
I attached the crash report from Friday. If it can help, I will try to get my corrupted session file for metacity next time the crash happens (but I would need some directions on where to get it).

[Thomas Meire (blackskad)]

I reproduced the bug this evening.
I logged in, moved the .gnome2/session file away, turned off session-saving, logged out and logged back in. Everything was back to normal then. When examining the session-file, there was no line for metacity (while there is one when everything is normal).
So I think this is what happens, which prevents metacity from starting:
* user presses logout
* metacity crashes and stays down
* gnome saves the state of the session, so without metacity running
* shutdown ----> boot
* user logs in
* gnome reads session file without metacity-line
=> result = no metacity started.
This bug (metacity not starting at login) should thus not happen when you don't save the state of the sessions.
Remaining question is why metacity crashes :)

In attachement is the .gnome2/session-file from right after the crash.

[Thomas Meire (blackskad)]

Metacity crash report from the crash described in https://bugs.launchpad.net/ubuntu/+source/metacity/+bug/106350/comments/8

[Thomas Meire (blackskad)]

I've ran strace a few minutes back. Metacity crashes with a segmentation fault. Backtrace is attached.

[Thomas Meire (blackskad)]

I've ran gdb and caught the segmentation fault. Backtrace is attached.

[Sebastien Bacher (seb128)]

Thank you for the work on the bug, I've opened one upstream on http://bugzilla.gnome.org/show_bug.cgi?id=433253

[Sebastien Bacher (seb128)]

The changes has been suggested by upstream and works correctly on my desktop

[Sebastien Bacher (seb128)]

the update has been approved by Martin on IRC while launchpad was down, I've uploaded it

[Martin Pitt (pitti)]

Accepted into feisty-proposed, please go ahead with QA testing. NB that this does not require a no-change -updates upload after verification (see updated SRU policy).

[Michael Vogt (mvo)]

I can reproduce the failure and verified that the fix works.
 I'm setting this to verificatin-done, it can go into feisty-updates at 2007-05-09.

[Marco Rodrigues (gothicx)]

I can confirm it too.. that's my crash report.

[Martin Pitt (pitti)]

Copied to feisty-updates.

[Adam Guthrie (ispiked)]

I was still hitting this even though I had the updated package with the fix in it installed. However, after I deleted ~/.gnome2/session the problem seems to be fixed. I have two questions: 1) have others experienced the same problem; i.e. experiencing this bug even with the updated package with a corrupt session file and 2) if this happens, is there anything we can do to fix it; e.g. delete the session file automatically somehow.

[Sebastien Bacher (seb128)]

it's also fixed in gutsy now

[willie.meyer (willie-meyer)]

Also worked for me to delete ~/.gnome2/session