ubuntu-sso-login crashed with SIGSEGV in QSocketNotifier::setEnabled()

[Paul White]

I looged out of Unity and into Gnome Shell.
The crash notification was displayed shortly after.

ProblemType: Crash
DistroRelease: Ubuntu 12.04
Package: ubuntu-sso-client 2.99.5-0ubuntu2
ProcVersionSignature: Ubuntu 3.2.0-17.27-generic-pae 3.2.6
Uname: Linux 3.2.0-17-generic-pae i686
ApportVersion: 1.93-0ubuntu2
Architecture: i386
Date: Fri Feb 24 22:22:47 2012
ExecutablePath: /usr/lib/ubuntu-sso-client/ubuntu-sso-login
InstallationMedia: Ubuntu 12.04 LTS "Precise Pangolin" - Alpha i386 (20120223.1)
InterpreterPath: /usr/bin/python2.7
PackageArchitecture: all
ProcCmdline: python /usr/lib/ubuntu-sso-client/ubuntu-sso-login
ProcEnviron:
 SHELL=/bin/bash
 PATH=(custom, no user)
 LANGUAGE=en_GB:en
 LANG=en_GB.UTF-8
SegvAnalysis:
 Segfault happened at: 0xb6bbf5de <_ZN15QSocketNotifier10setEnabledEb+30>: mov 0x24(%edx),%edx
 PC (0xb6bbf5de) ok
 source "0x24(%edx)" (0x00000024) not located in a known VMA region (needed readable region)!
 destination "%edx" ok
SegvReason: reading NULL VMA
Signal: 11
SourcePackage: ubuntu-sso-client
StacktraceTop:
 QSocketNotifier::setEnabled(bool) () from /usr/lib/i386-linux-gnu/libQtCore.so.4
 ?? () from /usr/lib/python2.7/dist-packages/dbus/mainloop/qt.so
 ?? () from /usr/lib/python2.7/dist-packages/dbus/mainloop/qt.so
 QMetaObject::activate(QObject*, QMetaObject const*, int, void**) () from /usr/lib/i386-linux-gnu/libQtCore.so.4
 QSocketNotifier::activated(int) () from /usr/lib/i386-linux-gnu/libQtCore.so.4
Title: ubuntu-sso-login crashed with SIGSEGV in QSocketNotifier::setEnabled()
UpgradeStatus: No upgrade log present (probably fresh install)
UserGroups: adm cdrom dip lpadmin plugdev sambashare sudo

[Apport retracing service (apport)]

StacktraceTop:
 ?? ()
 ?? ()
 qt_static_metacall (_a=0xbffced08, _o=0x966a5e0, _c=<optimized out>, _id=<optimized out>) at moc_helper.cpp:52
 pyqtDBusHelper::qt_static_metacall (_o=0x966a5e0, _c=QMetaObject::InvokeMetaMethod, _id=0, _a=0xbffced08) at moc_helper.cpp:46
 ?? ()

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Ubuntu QA Website (ubuntuqa)]

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://iso.qa.ubuntu.com/qatracker/reports/bugs/941468

[Sergio Schvezov (sergiusens)]

I'll add my scenario here, I was testing the unity staging ppas and after dist-upgrading it uninstalled unity (I did not notice that). When relogin in to test the new unity, I had an _idle_ session open with no unity (most of the other services loaded though), after a while, the crash occured.

[Alejandro J. Cura (alecu)]

This is caused by bug #334757. The pyqt bindings as used in the new version of ubuntu-sso-client are crashing in the same way as they crash in said pyqt bug when the dbus connection is interrupted.
I've also added a script that shows how this breaks to that bug.

[Alejandro J. Cura (alecu)]

The fix for the pyqt bug has been solved upstream, and is now packaged in -proposed.
I'm marking this bug as invalid for ubuntu-sso-client.