Application: kwin_x11 (5.2.2)

Qt Version: 5.4.1
Operating System: Linux 3.19.0-25-generic x86_64
Distribution: Ubuntu 15.04

-- Information about the crash:
- What I was doing when the application crashed:
Logging into plasma from sddm causes kwin_x11 to crash reliably. this happens consistently every time I log in. Activating Xinerama actually got me far enough to generate this bug report.
- Custom settings of the application:
4 monitors, 2 GPUs, Nvidia with Xinerama. I haven't tried Twinview yet.

The crash can be reproduced every time.

-- Backtrace:
Application: KWin (kwin_x11), signal: Segmentation fault
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
[KCrash Handler]
#6  xcb_setup_vendor_end (R=R@entry=0x0) at xproto.c:1569
#7  0x00007fa66bb79059 in xcb_setup_pixmap_formats_iterator (R=R@entry=0x0) at xproto.c:1622
#8  0x00007fa66bb79099 in xcb_setup_roots_iterator (R=0x0) at xproto.c:1659
#9  0x00007fa66d3990f8 in defaultScreen () at ../libkwineffects/kwinglobals.h:170
#10 KWin::ColorMapper::ColorMapper (this=this@entry=0xe5c5e0, parent=parent@entry=0xe25140) at ../workspace.cpp:82
#11 0x00007fa66d3a1371 in KWin::Workspace::Workspace (this=0xe25140, restore=<optimized out>) at ../workspace.cpp:172
#12 0x00007fa66db46aa6 in operator() (__closure=<synthetic pointer>) at ../main_x11.cpp:170
#13 call (arg=<optimized out>, f=...) at /usr/include/x86_64-linux-gnu/qt5/QtCore/qobjectdefs_impl.h:494
#14 call<QtPrivate::List<>, void> (arg=<optimized out>, f=...) at /usr/include/x86_64-linux-gnu/qt5/QtCore/qobjectdefs_impl.h:551
#15 QtPrivate::QFunctorSlotObject<KWin::ApplicationX11::performStartup()::<lambda()>, 0, QtPrivate::List<>, void>::impl(int, QtPrivate::QSlotObjectBase *, QObject *, void **, bool *) (which=<optimized out>, this_=<optimized out>, r=<optimized out>, a=<optimized out>, ret=<optimized out>) at /usr/include/x86_64-linux-gnu/qt5/QtCore/qobject_impl.h:192
#16 0x00007fa66c09c35a in call (a=0x7ffc448d7bf0, r=0xd9a350, this=0xd9b7c0) at ../../include/QtCore/../../src/corelib/kernel/qobject_impl.h:124
#17 QMetaObject::activate (sender=0xd9a350, signalOffset=<optimized out>, local_signal_index=local_signal_index@entry=1, argv=argv@entry=0x0) at kernel/qobject.cpp:3702
#18 0x00007fa66c09d057 in QMetaObject::activate (sender=<optimized out>, m=m@entry=0x7fa66d111bc0 <KSelectionOwner::staticMetaObject>, local_signal_index=local_signal_index@entry=1, argv=argv@entry=0x0) at kernel/qobject.cpp:3582
#19 0x00007fa66cf010e3 in KSelectionOwner::claimedOwnership (this=<optimized out>) at moc_kselectionowner.cpp:150
#20 0x00007fa66cee4a9b in KSelectionOwner::Private::claimSucceeded (this=0xda7a70) at ../../src/kselectionowner.cpp:206
#21 0x00007fa66cee5221 in KSelectionOwner::filterEvent (this=0xd9a350, ev_P=<optimized out>) at ../../src/kselectionowner.cpp:424
#22 0x00007fa66c068510 in QAbstractEventDispatcher::filterNativeEvent (this=this@entry=0xd76be0, eventType=..., message=message@entry=0x7fa650001c10, result=result@entry=0x7ffc448d7d88) at kernel/qabstracteventdispatcher.cpp:460
#23 0x00007fa656fed02d in QXcbConnection::handleXcbEvent (this=this@entry=0xd46180, event=event@entry=0x7fa650001c10) at qxcbconnection.cpp:863
#24 0x00007fa656fee4bb in QXcbConnection::processXcbEvents (this=0xd46180) at qxcbconnection.cpp:1303
#25 0x00007fa66c09d73a in QObject::event (this=0xd46180, e=<optimized out>) at kernel/qobject.cpp:1245
#26 0x00007fa66c975b2c in QApplicationPrivate::notify_helper (this=0xd372e0, receiver=0xd46180, e=0x7fa650002330) at kernel/qapplication.cpp:3720
#27 0x00007fa66c97b000 in QApplication::notify (this=0x7ffc448d8470, receiver=0xd46180, e=0x7fa650002330) at kernel/qapplication.cpp:3503
#28 0x00007fa66c06bc2b in QCoreApplication::notifyInternal (this=0x7ffc448d8470, receiver=0xd46180, event=event@entry=0x7fa650002330) at kernel/qcoreapplication.cpp:935
#29 0x00007fa66c06dc9b in sendEvent (event=0x7fa650002330, receiver=<optimized out>) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:228
#30 QCoreApplicationPrivate::sendPostedEvents (receiver=receiver@entry=0x0, event_type=event_type@entry=0, data=0xd28190) at kernel/qcoreapplication.cpp:1552
#31 0x00007fa66c0c2112 in QEventDispatcherUNIX::processEvents (this=0xd76be0, flags=flags@entry=...) at kernel/qeventdispatcher_unix.cpp:579
#32 0x00007fa65704496d in QUnixEventDispatcherQPA::processEvents (this=<optimized out>, flags=...) at eventdispatchers/qunixeventdispatcher.cpp:62
#33 0x00007fa66c0693e2 in QEventLoop::exec (this=this@entry=0x7ffc448d8390, flags=..., flags@entry=...) at kernel/qeventloop.cpp:204
#34 0x00007fa66c07102c in QCoreApplication::exec () at kernel/qcoreapplication.cpp:1188
#35 0x00007fa66c3b031c in QGuiApplication::exec () at kernel/qguiapplication.cpp:1510
#36 0x00007fa66c9717a5 in QApplication::exec () at kernel/qapplication.cpp:2956
#37 0x00007fa66db478c3 in kdemain (argc=3, argv=0x7ffc448d85c8) at ../main_x11.cpp:294
#38 0x00007fa66d799a40 in __libc_start_main (main=0x400790 <main(int, char**)>, argc=3, argv=0x7ffc448d85c8, init=<optimized out>, fini=<optimized out>, rtld_fini=<optimized out>, stack_end=0x7ffc448d85b8) at libc-start.c:289
#39 0x00000000004007c9 in _start ()

Reported using DrKonqi