compiz assert failure: compiz: /usr/include/boost/smart_ptr/shared_ptr.hpp:418: T* boost::shared_ptr<T>::operator->() const [with T = UnityFBO]: Assertion `px != 0' failed.

[Pete Goodall]

When I plug my monitor into my laptop (VGA) it is setup to be the primary display and the laptop LCD is shutoff. I decided I wanted to make the laptop the primary and the monitor the extended, so I went into the gnome-display-properties dialog and turned on the LCD display. After about 10 seconds the monitor blanked and the light went amber (as opposed to blue when it is connected) and my laptop LCD displayed what looked like the extended screen. I canceled that change and went back to the previous setup. I tried again with the same settings and this time both screens went blank, the monitor finally showed something (that appeared to be an extended screen) and finally compiz crashed. Let me know if you need more debugging data.

ProblemType: Crash
DistroRelease: Ubuntu 11.10
Package: unity 4.16.0-0ubuntu1
ProcVersionSignature: Ubuntu 3.0.0-11.18-generic 3.0.4
Uname: Linux 3.0.0-11-generic x86_64
ApportVersion: 1.23-0ubuntu1
Architecture: amd64
AssertionMessage: compiz: /usr/include/boost/smart_ptr/shared_ptr.hpp:418: T* boost::shared_ptr<T>::operator->() const [with T = UnityFBO]: Assertion `px != 0' failed.
CrashCounter: 1
Date: Mon Sep 19 15:49:28 2011
ExecutablePath: /usr/bin/compiz
InstallationMedia: Ubuntu 11.10 "Oneiric Ocelot" - Alpha amd64 (20110728)
ProcCmdline: compiz
ProcEnviron:
 LANGUAGE=en_GB:en
 PATH=(custom, user)
 LANG=en_GB.UTF-8
 SHELL=/bin/bash
Signal: 6
SourcePackage: unity
StacktraceTop:
 raise () from /lib/x86_64-linux-gnu/libc.so.6
 abort () from /lib/x86_64-linux-gnu/libc.so.6
 __assert_fail () from /lib/x86_64-linux-gnu/libc.so.6
 UnityScreen::glPaintOutput(GLScreenPaintAttrib const&, GLMatrix const&, CompRegion const&, CompOutput*, unsigned int) () from /usr/lib/compiz/libunityshell.so
 GLScreen::glPaintOutput(GLScreenPaintAttrib const&, GLMatrix const&, CompRegion const&, CompOutput*, unsigned int) () from /usr/lib/compiz/libopengl.so
Title: compiz assert failure: compiz: /usr/include/boost/smart_ptr/shared_ptr.hpp:418: T* boost::shared_ptr<T>::operator->() const [with T = UnityFBO]: Assertion `px != 0' failed.
UpgradeStatus: No upgrade log present (probably fresh install)
UserGroups: adm admin cdrom dialout lpadmin plugdev sambashare

[Apport retracing service (apport)]

Thank you for taking the time to report this crash and helping to make Ubuntu better. This particular crash has already been reported and is a duplicate of bug #838128, so is being marked as such. Please look at the other bug report to see if there is any missing information that you can provide, or to see if there is a workaround for the bug. Additionally, any further discussion regarding the bug should occur in the other report. Please continue to report any other bugs you may find.