Application: kwin (4.11.6)
KDE Platform Version: 4.12.90
Qt Version: 4.8.6
Operating System: Linux 3.13.0-18-generic x86_64
Distribution: Ubuntu Trusty Tahr (development branch)

-- Information about the crash:
- What I was doing when the application crashed:

Crash after a full dist-upgrade of Kubuntu 14.04, last catalyst installed on this system.

-- Backtrace:
Application: KWin (kwin), signal: Segmentation fault
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
[KCrash Handler]
#6  GetDrawableAttribute (dpy=0x1836c40, drawable=27263008, attribute=8436, value=0x1a23ea0) at ../../../../src/glx/glx_pbuffer.c:322
#7  0x00007f67febac94b in KWin::GlxBackend::present (this=0x1a23b10) at ../../kwin/glxbackend.cpp:475
#8  0x00007f67febac0b9 in KWin::GlxBackend::endRenderingFrame (this=0x1a23b10, renderedRegion=..., damagedRegion=...) at ../../kwin/glxbackend.cpp:564
#9  0x00007f67feba6912 in KWin::SceneOpenGL::paint (this=this@entry=0x1a195f0, damage=..., toplevels=...) at ../../kwin/scene_opengl.cpp:409
#10 0x00007f67feba6bf7 in KWin::SceneOpenGL1::paint (this=0x1a195f0, damage=..., windows=...) at ../../kwin/scene_opengl.cpp:875
#11 0x00007f67feb8b6e3 in KWin::Compositor::performCompositing (this=this@entry=0x19a5ec0) at ../../kwin/composite.cpp:618
#12 0x00007f67feb8c9df in KWin::Compositor::slotCompositingOptionsInitialized (this=0x19a5ec0) at ../../kwin/composite.cpp:273
#13 0x00007f67feb14b75 in KWin::Compositor::qt_static_metacall (_o=<optimized out>, _id=<optimized out>, _a=<optimized out>, _c=<optimized out>) at moc_composite.cpp:193
#14 0x00007f67f8bd087a in QMetaObject::activate (sender=0x1a82440, m=<optimized out>, local_signal_index=<optimized out>, argv=0x0) at kernel/qobject.cpp:3539
#15 0x00007f67f8aaab18 in QFutureWatcherBase::event (this=<optimized out>, event=0x7f67d40013c0) at concurrent/qfuturewatcher.cpp:344
#16 0x00007f67f7f55e2c in QApplicationPrivate::notify_helper (this=this@entry=0x1802650, receiver=receiver@entry=0x1a82440, e=e@entry=0x7f67d40013c0) at kernel/qapplication.cpp:4567
#17 0x00007f67f7f5c4a0 in QApplication::notify (this=this@entry=0x7fffabbba0d0, receiver=receiver@entry=0x1a82440, e=e@entry=0x7f67d40013c0) at kernel/qapplication.cpp:4353
#18 0x00007f67fd442b9a in KApplication::notify (this=0x7fffabbba0d0, receiver=0x1a82440, event=0x7f67d40013c0) at ../../kdeui/kernel/kapplication.cpp:311
#19 0x00007f67f8bbc4dd in QCoreApplication::notifyInternal (this=0x7fffabbba0d0, receiver=receiver@entry=0x1a82440, event=event@entry=0x7f67d40013c0) at kernel/qcoreapplication.cpp:953
#20 0x00007f67f8bbfb3d in sendEvent (event=0x7f67d40013c0, receiver=0x1a82440) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:231
#21 QCoreApplicationPrivate::sendPostedEvents (receiver=receiver@entry=0x0, event_type=event_type@entry=0, data=0x17a31f0) at kernel/qcoreapplication.cpp:1577
#22 0x00007f67f8bbffe3 in QCoreApplication::sendPostedEvents (receiver=receiver@entry=0x0, event_type=event_type@entry=0) at kernel/qcoreapplication.cpp:1470
#23 0x00007f67f7ff832c in sendPostedEvents () at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:236
#24 QEventDispatcherX11::processEvents (this=0x17a4af0, flags=...) at kernel/qeventdispatcher_x11.cpp:75
#25 0x00007f67f8bbb0af in QEventLoop::processEvents (this=this@entry=0x7fffabbb9f40, flags=...) at kernel/qeventloop.cpp:149
#26 0x00007f67f8bbb3a5 in QEventLoop::exec (this=this@entry=0x7fffabbb9f40, flags=...) at kernel/qeventloop.cpp:204
#27 0x00007f67f8bc0b79 in QCoreApplication::exec () at kernel/qcoreapplication.cpp:1225
#28 0x00007f67f7f5437c in QApplication::exec () at kernel/qapplication.cpp:3828
#29 0x00007f67feb45856 in kdemain (argc=3, argv=0x7fffabbba218) at ../../kwin/main.cpp:597
#30 0x00007f67fe725ec5 in __libc_start_main (main=0x4006d0 <main(int, char**)>, argc=3, argv=0x7fffabbba218, init=<optimized out>, fini=<optimized out>, rtld_fini=<optimized out>, stack_end=0x7fffabbba208) at libc-start.c:285
#31 0x00000000004006fe in _start ()

Reported using DrKonqi