Application: plasmashell (5.4.2)
 (Compiled from sources)
Qt Version: 5.5.1
Operating System: Linux 4.0.5-gentoo-gnu-f1r31c3r-NV x86_64
Distribution: "NAME=Gentoo"

-- Information about the crash:
- What I was doing when the application crashed:
Starting KDE from startx. startup screen loads, no animation loading bar in breeze and it then just hangs.
Droping to a second shell and using the kill command to kill kwin_x11 allows me to break the hung crash. 
Killing plasmashell and kwin sometimes allows me to get into kde gui to read the crash report assistant.

The crash can be reproduced every time.

-- Backtrace:
Application: Plasma (plasmashell), signal: Segmentation fault
Using host libthread_db library "/lib64/libthread_db.so.1".
[Current thread is 1 (Thread 0x7fe8a1c78780 (LWP 18473))]

Thread 8 (Thread 0x7fe88d54a700 (LWP 18475)):
#0  0x00007fe89c59fe4d in poll () from /lib64/libc.so.6
#1  0x00007fe8a04879a2 in _xcb_conn_wait () from /usr/lib64/libxcb.so.1
#2  0x00007fe8a048947f in xcb_wait_for_event () from /usr/lib64/libxcb.so.1
#3  0x00007fe88fedb6d9 in QXcbEventReader::run() () from /usr/lib64/libQt5XcbQpa.so.5
#4  0x00007fe89cc10ca3 in QThreadPrivate::start(void*) () from /usr/lib64/libQt5Core.so.5
#5  0x00007fe89bdb043a in start_thread () from /lib64/libpthread.so.0
#6  0x00007fe89c5a8f6d in clone () from /lib64/libc.so.6

Thread 7 (Thread 0x7fe886548700 (LWP 18484)):
#0  0x00007fe89c59be2d in read () from /lib64/libc.so.6
#1  0x00007fe8954b5073 in ?? () from /usr/lib64/libnvidia-tls.so.355.11
#2  0x00007fe89862fa70 in g_wakeup_acknowledge () from /usr/lib64/libglib-2.0.so.0
#3  0x00007fe8985ee849 in g_main_context_check () from /usr/lib64/libglib-2.0.so.0
#4  0x00007fe8985eec68 in g_main_context_iterate.isra () from /usr/lib64/libglib-2.0.so.0
#5  0x00007fe8985eedec in g_main_context_iteration () from /usr/lib64/libglib-2.0.so.0
#6  0x00007fe89cdfc3eb in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib64/libQt5Core.so.5
#7  0x00007fe89cdb0edb in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib64/libQt5Core.so.5
#8  0x00007fe89cc0c58a in QThread::exec() () from /usr/lib64/libQt5Core.so.5
#9  0x00007fe89f349a58 in QQmlThreadPrivate::run() () from /usr/lib64/libQt5Qml.so.5
#10 0x00007fe89cc10ca3 in QThreadPrivate::start(void*) () from /usr/lib64/libQt5Core.so.5
#11 0x00007fe89bdb043a in start_thread () from /lib64/libpthread.so.0
#12 0x00007fe89c5a8f6d in clone () from /lib64/libc.so.6

Thread 6 (Thread 0x7fe87e64c700 (LWP 18515)):
#0  0x00007fe89c59fe4d in poll () from /lib64/libc.so.6
#1  0x00007fe8985eecd4 in g_main_context_iterate.isra () from /usr/lib64/libglib-2.0.so.0
#2  0x00007fe8985eedec in g_main_context_iteration () from /usr/lib64/libglib-2.0.so.0
#3  0x00007fe89cdfc3eb in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib64/libQt5Core.so.5
#4  0x00007fe89cdb0edb in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib64/libQt5Core.so.5
#5  0x00007fe89cc0c58a in QThread::exec() () from /usr/lib64/libQt5Core.so.5
#6  0x00007fe89f349a58 in QQmlThreadPrivate::run() () from /usr/lib64/libQt5Qml.so.5
#7  0x00007fe89cc10ca3 in QThreadPrivate::start(void*) () from /usr/lib64/libQt5Core.so.5
#8  0x00007fe89bdb043a in start_thread () from /lib64/libpthread.so.0
#9  0x00007fe89c5a8f6d in clone () from /lib64/libc.so.6

Thread 5 (Thread 0x7fe87cc85700 (LWP 18519)):
#0  0x00007fe89c59fe4d in poll () from /lib64/libc.so.6
#1  0x00007fe8985eecd4 in g_main_context_iterate.isra () from /usr/lib64/libglib-2.0.so.0
#2  0x00007fe8985eedec in g_main_context_iteration () from /usr/lib64/libglib-2.0.so.0
#3  0x00007fe89cdfc3eb in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib64/libQt5Core.so.5
#4  0x00007fe89cdb0edb in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib64/libQt5Core.so.5
#5  0x00007fe89cc0c58a in QThread::exec() () from /usr/lib64/libQt5Core.so.5
#6  0x00007fe89f349a58 in QQmlThreadPrivate::run() () from /usr/lib64/libQt5Qml.so.5
#7  0x00007fe89cc10ca3 in QThreadPrivate::start(void*) () from /usr/lib64/libQt5Core.so.5
#8  0x00007fe89bdb043a in start_thread () from /lib64/libpthread.so.0
#9  0x00007fe89c5a8f6d in clone () from /lib64/libc.so.6

Thread 4 (Thread 0x7fe8771c3700 (LWP 18532)):
#0  0x00007fe89bdb5f40 in pthread_cond_wait () from /lib64/libpthread.so.0
#1  0x00007fe8a16dd54b in QTWTF::TCMalloc_PageHeap::scavengerThread() () from /usr/lib64/libQt5Script.so.5
#2  0x00007fe8a16dd579 in QTWTF::TCMalloc_PageHeap::runScavengerThread(void*) () from /usr/lib64/libQt5Script.so.5
#3  0x00007fe89bdb043a in start_thread () from /lib64/libpthread.so.0
#4  0x00007fe89c5a8f6d in clone () from /lib64/libc.so.6

Thread 3 (Thread 0x7fe7effff700 (LWP 18546)):
#0  0x00007fe89c59fe4d in poll () from /lib64/libc.so.6
#1  0x00007fe8985eecd4 in g_main_context_iterate.isra () from /usr/lib64/libglib-2.0.so.0
#2  0x00007fe8985eedec in g_main_context_iteration () from /usr/lib64/libglib-2.0.so.0
#3  0x00007fe89cdfc3eb in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib64/libQt5Core.so.5
#4  0x00007fe89cdb0edb in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib64/libQt5Core.so.5
#5  0x00007fe89cc0c58a in QThread::exec() () from /usr/lib64/libQt5Core.so.5
#6  0x00007fe89fcd10e2 in QQuickPixmapReader::run() () from /usr/lib64/libQt5Quick.so.5
#7  0x00007fe89cc10ca3 in QThreadPrivate::start(void*) () from /usr/lib64/libQt5Core.so.5
#8  0x00007fe89bdb043a in start_thread () from /lib64/libpthread.so.0
#9  0x00007fe89c5a8f6d in clone () from /lib64/libc.so.6

Thread 2 (Thread 0x7fe7ee621700 (LWP 18562)):
[KCrash Handler]
#6  0x00007fe89c559e7d in __strstr_sse2_unaligned () from /lib64/libc.so.6
#7  0x00007fe89fd246ea in QSGRenderContext::initialize(QOpenGLContext*) () from /usr/lib64/libQt5Quick.so.5
#8  0x00007fe89fd422d1 in QSGRenderThread::run() () from /usr/lib64/libQt5Quick.so.5
#9  0x00007fe89cc10ca3 in QThreadPrivate::start(void*) () from /usr/lib64/libQt5Core.so.5
#10 0x00007fe89bdb043a in start_thread () from /lib64/libpthread.so.0
#11 0x00007fe89c5a8f6d in clone () from /lib64/libc.so.6

Thread 1 (Thread 0x7fe8a1c78780 (LWP 18473)):
#0  0x00007fe89bdb5f40 in pthread_cond_wait () from /lib64/libpthread.so.0
#1  0x00007fe89cc1129a in QWaitCondition::wait(QMutex*, unsigned long) () from /usr/lib64/libQt5Core.so.5
#2  0x00007fe89fd434ae in QSGThreadedRenderLoop::polishAndSync(QSGThreadedRenderLoop::Window*, bool) () from /usr/lib64/libQt5Quick.so.5
#3  0x00007fe89fd454a2 in QSGThreadedRenderLoop::handleExposure(QQuickWindow*) () from /usr/lib64/libQt5Quick.so.5
#4  0x00007fe89fd45b0b in QSGThreadedRenderLoop::exposureChanged(QQuickWindow*) () from /usr/lib64/libQt5Quick.so.5
#5  0x00007fe89d0e3559 in QWindow::event(QEvent*) () from /usr/lib64/libQt5Gui.so.5
#6  0x00007fe89fd76991 in QQuickWindow::event(QEvent*) () from /usr/lib64/libQt5Quick.so.5
#7  0x000000000043e806 in DesktopView::event(QEvent*) ()
#8  0x00007fe89d7ef7ec in QApplicationPrivate::notify_helper(QObject*, QEvent*) () from /usr/lib64/libQt5Widgets.so.5
#9  0x00007fe89d7f4610 in QApplication::notify(QObject*, QEvent*) () from /usr/lib64/libQt5Widgets.so.5
#10 0x00007fe89cdb22ad in QCoreApplication::notifyInternal(QObject*, QEvent*) () from /usr/lib64/libQt5Core.so.5
#11 0x00007fe89d0dc734 in QGuiApplicationPrivate::processExposeEvent(QWindowSystemInterfacePrivate::ExposeEvent*) () from /usr/lib64/libQt5Gui.so.5
#12 0x00007fe89d0dd32d in QGuiApplicationPrivate::processWindowSystemEvent(QWindowSystemInterfacePrivate::WindowSystemEvent*) () from /usr/lib64/libQt5Gui.so.5
#13 0x00007fe89d0c3418 in QWindowSystemInterface::sendWindowSystemEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib64/libQt5Gui.so.5
#14 0x00007fe88ff062e0 in userEventSourceDispatch(_GSource*, int (*)(void*), void*) () from /usr/lib64/libQt5XcbQpa.so.5
#15 0x00007fe8985eea1a in g_main_context_dispatch () from /usr/lib64/libglib-2.0.so.0
#16 0x00007fe8985eed48 in g_main_context_iterate.isra () from /usr/lib64/libglib-2.0.so.0
#17 0x00007fe8985eedec in g_main_context_iteration () from /usr/lib64/libglib-2.0.so.0
#18 0x00007fe89cdfc3cc in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib64/libQt5Core.so.5
#19 0x00007fe89cdb0edb in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib64/libQt5Core.so.5
#20 0x00007fe89cdb7e16 in QCoreApplication::exec() () from /usr/lib64/libQt5Core.so.5
#21 0x000000000043238b in main ()

Possible duplicates by query: bug 353520, bug 350022, bug 348812.

Reported using DrKonqi