unity-2d-panel crashed with SIGSEGV in QConfSchema::findKey()

StacktraceTop:
 QConfSchema::findKey(char const*) const () from /tmp/tmp080XGq/usr/lib/libdconf-qt.so.0
 QConf::notify(char const*) () from /tmp/tmp080XGq/usr/lib/libdconf-qt.so.0
 ?? () from /tmp/tmp080XGq/usr/lib/libdconf-qt.so.0
 add_match_done (pending=0x9cc8350, user_data=0x9c44180) at dconf-dbus-1.c:569
 ?? () from /tmp/tmp080XGq/lib/i386-linux-gnu/libdbus-1.so.3

Thanks for taking the time to report this bug and helping to make Ubuntu better. We appreciate the difficulties you are facing, but this appears to be a "regular" (non-security) bug. I have unmarked it as a security issue since this bug does not show evidence of allowing attackers to cross privilege boundaries nor directly cause loss of data/privacy. Please feel free to report any other bugs you may find.

Got the same after a dist-upgrade from the update manager yesterday (27-08-2011) and rebooting, then I logged in and this popped up. I'm not sure wether I opened an application but I don't think it has anything to do with this crash.

The crash is reproducible from revision 658 onwards. Probably something is wrong with the panel plugins dconf schema.

The QConf object we allocate when instantiating the panel gets destroyed before we enter the main loop, but its destructor doesn't remove the connection to DConf's notify signal, which later gets emitted from the main loop. At that point our QConf instance is already destroyed, and hence the crash.
We can work around it in the panel, by simply not destroying the QConf instance, but we can hopefully get it fixed in QConf as well.

Happened after first boot of daily build in Virtual Box.

This bug was fixed in the package unity-2d - 4.4.0-0ubuntu1

---------------
unity-2d (4.4.0-0ubuntu1) oneiric; urgency=low

  * New upstream release:
    - unity-2d-panel crashed with SIGSEGV in QConfSchema::findKey()
      (LP: #834045)
    - unity-2d-panel crashed with SIGSEGV in QConf::notify() (LP: #834001)
    - [panel] Implement whitelisting for legacy tray applet (LP: #707354)
    - [launcher] stops automatically hiding after some time using it
      (LP: #821180)
    - [panel] Empathy displays icon in deprecated systray (LP: #830017)
    - [dash] Invalid UTF-8 in the dash (LP: #836587)
    - [dash] Home buttons 'Media' and 'Internet' apps should not only take you
      to the apps lens but also activate the right filter (LP: #837360)
    - [dash] Drag&drop application from dash to launcher is broken
      (LP: #837361)
    - [launcher] contextual menu's corner has a blue line (LP: #828386)
    - [dash] Lens bar graphical layout glitches (LP: #833805)
    - [dash] Rating Filter: All button not clearing star highlighting
      (LP: #834640)
    - [dash] should be falling back to the default renderer if the renderer
      requested by the lens is not found (LP: #837356)
    - [dash] Gwibber lens icon doesn't show up in 2d unity (LP: #830728)
    - [dash] Lacks horizontal renderer used by lenses such as Gwibber
      (LP: #837712)
    - [dash] See %1 more result inconsistency (LP: #834226)
    - [launcher] When application has no icon, a question mark icon should be
      displayed (LP: #837351)
    - unity places should return a default icon when no matching icon is found
      (LP: #711200)
    - spacing between indicators should be 5 pixels (LP: #734010)
  * debian/control:
    - require current nux and unity
 -- Didier Roche <email address hidden> Thu, 01 Sep 2011 17:41:00 +0200