Application: plasmashell (5.5.5)
 (Compiled from sources)
Qt Version: 5.5.1
Operating System: Linux 4.4.0-22-generic x86_64
Distribution: Ubuntu 16.04 LTS

-- Information about the crash:
- What I was doing when the application crashed:
2 sessions was opened on the computer, when I get back to the first session I got message that there is an issue and have to type 'loginctl unlock-sessions' to access to my previous session.
Once done I get plasma crash information and have to launch it back.

-- Backtrace:
Application: Plasma (plasmashell), signal: Segmentation fault
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
pthread_cond_wait@@GLIBC_2.3.2 () at ../sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185
[Current thread is 1 (Thread 0x7f992b1968c0 (LWP 4418))]

Thread 8 (Thread 0x7f99173ea700 (LWP 4421)):
#0  0x00007f99258a1e8d in poll () at ../sysdeps/unix/syscall-template.S:84
#1  0x00007f9929966c62 in ?? () from /usr/lib/x86_64-linux-gnu/libxcb.so.1
#2  0x00007f99299688d7 in xcb_wait_for_event () from /usr/lib/x86_64-linux-gnu/libxcb.so.1
#3  0x00007f9919b6a629 in QXcbEventReader::run (this=0x197c950) at qxcbconnection.cpp:1253
#4  0x00007f9925f9784e in QThreadPrivate::start (arg=0x197c950) at thread/qthread_unix.cpp:331
#5  0x00007f99250846fa in start_thread (arg=0x7f99173ea700) at pthread_create.c:333
#6  0x00007f99258adb5d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 7 (Thread 0x7f990ffff700 (LWP 4423)):
#0  0x00007f99258a1e8d in poll () at ../sysdeps/unix/syscall-template.S:84
#1  0x00007f992263731c in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#2  0x00007f992263742c in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#3  0x00007f99261cea9b in QEventDispatcherGlib::processEvents (this=0x7f99080008c0, flags=...) at kernel/qeventdispatcher_glib.cpp:420
#4  0x00007f9926175dea in QEventLoop::exec (this=this@entry=0x7f990fffece0, flags=..., flags@entry=...) at kernel/qeventloop.cpp:204
#5  0x00007f9925f928a4 in QThread::exec (this=this@entry=0x1a50270) at thread/qthread.cpp:503
#6  0x00007f992883a3c5 in QQmlThreadPrivate::run (this=0x1a50270) at qml/ftw/qqmlthread.cpp:141
#7  0x00007f9925f9784e in QThreadPrivate::start (arg=0x1a50270) at thread/qthread_unix.cpp:331
#8  0x00007f99250846fa in start_thread (arg=0x7f990ffff700) at pthread_create.c:333
#9  0x00007f99258adb5d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 6 (Thread 0x7f9904101700 (LWP 4424)):
#0  0x00007f992267ba64 in g_mutex_unlock () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#1  0x00007f992263631e in g_main_context_acquire () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#2  0x00007f99226371d5 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#3  0x00007f992263742c in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#4  0x00007f99261cea9b in QEventDispatcherGlib::processEvents (this=0x7f98fc0008c0, flags=...) at kernel/qeventdispatcher_glib.cpp:420
#5  0x00007f9926175dea in QEventLoop::exec (this=this@entry=0x7f9904100ce0, flags=..., flags@entry=...) at kernel/qeventloop.cpp:204
#6  0x00007f9925f928a4 in QThread::exec (this=this@entry=0x1d10a90) at thread/qthread.cpp:503
#7  0x00007f992883a3c5 in QQmlThreadPrivate::run (this=0x1d10a90) at qml/ftw/qqmlthread.cpp:141
#8  0x00007f9925f9784e in QThreadPrivate::start (arg=0x1d10a90) at thread/qthread_unix.cpp:331
#9  0x00007f99250846fa in start_thread (arg=0x7f9904101700) at pthread_create.c:333
#10 0x00007f99258adb5d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 5 (Thread 0x7f9902259700 (LWP 4425)):
#0  0x00007f99258a1e8d in poll () at ../sysdeps/unix/syscall-template.S:84
#1  0x00007f992263731c in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#2  0x00007f992263742c in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#3  0x00007f99261cea9b in QEventDispatcherGlib::processEvents (this=0x7f98f40008c0, flags=...) at kernel/qeventdispatcher_glib.cpp:420
#4  0x00007f9926175dea in QEventLoop::exec (this=this@entry=0x7f9902258ce0, flags=..., flags@entry=...) at kernel/qeventloop.cpp:204
#5  0x00007f9925f928a4 in QThread::exec (this=this@entry=0x1efb0a0) at thread/qthread.cpp:503
#6  0x00007f992883a3c5 in QQmlThreadPrivate::run (this=0x1efb0a0) at qml/ftw/qqmlthread.cpp:141
#7  0x00007f9925f9784e in QThreadPrivate::start (arg=0x1efb0a0) at thread/qthread_unix.cpp:331
#8  0x00007f99250846fa in start_thread (arg=0x7f9902259700) at pthread_create.c:333
#9  0x00007f99258adb5d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 4 (Thread 0x7f99008ec700 (LWP 4426)):
#0  pthread_cond_wait@@GLIBC_2.3.2 () at ../sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185
#1  0x00007f992abdfbd4 in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Script.so.5
#2  0x00007f992abdfc19 in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Script.so.5
#3  0x00007f99250846fa in start_thread (arg=0x7f99008ec700) at pthread_create.c:333
#4  0x00007f99258adb5d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 3 (Thread 0x7f98f9a68700 (LWP 4428)):
#0  0x00007f99258a1e8d in poll () at ../sysdeps/unix/syscall-template.S:84
#1  0x00007f992263731c in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#2  0x00007f992263742c in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#3  0x00007f99261cea9b in QEventDispatcherGlib::processEvents (this=0x7f98700008c0, flags=...) at kernel/qeventdispatcher_glib.cpp:420
#4  0x00007f9926175dea in QEventLoop::exec (this=this@entry=0x7f98f9a67c90, flags=..., flags@entry=...) at kernel/qeventloop.cpp:204
#5  0x00007f9925f928a4 in QThread::exec (this=this@entry=0x2151900) at thread/qthread.cpp:503
#6  0x00007f99291c0ed6 in QQuickPixmapReader::run (this=0x2151900) at util/qquickpixmapcache.cpp:817
#7  0x00007f9925f9784e in QThreadPrivate::start (arg=0x2151900) at thread/qthread_unix.cpp:331
#8  0x00007f99250846fa in start_thread (arg=0x7f98f9a68700) at pthread_create.c:333
#9  0x00007f99258adb5d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 2 (Thread 0x7f98f8d75700 (LWP 4429)):
[KCrash Handler]
#6  __strstr_sse2_unaligned () at ../sysdeps/x86_64/multiarch/strstr-sse2-unaligned.S:40
#7  0x00007f9929213aca in strstr (__needle=0x7f99293b0fdf "nouveau", __haystack=<optimized out>) at /usr/include/string.h:332
#8  QSGRenderContext::initialize (this=0x1fdea80, context=<optimized out>) at scenegraph/qsgcontext.cpp:659
#9  0x00007f9929237409 in QSGRenderThread::run (this=0x1d76af0) at scenegraph/qsgthreadedrenderloop.cpp:676
#10 0x00007f9925f9784e in QThreadPrivate::start (arg=0x1d76af0) at thread/qthread_unix.cpp:331
#11 0x00007f99250846fa in start_thread (arg=0x7f98f8d75700) at pthread_create.c:333
#12 0x00007f99258adb5d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 1 (Thread 0x7f992b1968c0 (LWP 4418)):
#0  pthread_cond_wait@@GLIBC_2.3.2 () at ../sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185
#1  0x00007f9925f98aeb in QWaitConditionPrivate::wait (time=18446744073709551615, this=0x208c950) at thread/qwaitcondition_unix.cpp:136
#2  QWaitCondition::wait (this=<optimized out>, mutex=0x1d76b30, time=time@entry=18446744073709551615) at thread/qwaitcondition_unix.cpp:208
#3  0x00007f9929233bc6 in QSGThreadedRenderLoop::polishAndSync (this=this@entry=0x1bb3450, w=<optimized out>, w@entry=0x2156e00, inExpose=inExpose@entry=true) at scenegraph/qsgthreadedrenderloop.cpp:1150
#4  0x00007f992923609c in QSGThreadedRenderLoop::handleExposure (this=this@entry=0x1bb3450, window=window@entry=0x202efd0) at scenegraph/qsgthreadedrenderloop.cpp:946
#5  0x00007f9929236733 in QSGThreadedRenderLoop::exposureChanged (this=0x1bb3450, window=0x202efd0) at scenegraph/qsgthreadedrenderloop.cpp:857
#6  0x00007f99264c32f5 in QWindow::event (this=this@entry=0x202efd0, ev=ev@entry=0x7fffda1d6fd0) at kernel/qwindow.cpp:2060
#7  0x00007f9929269871 in QQuickWindow::event (this=this@entry=0x202efd0, e=e@entry=0x7fffda1d6fd0) at items/qquickwindow.cpp:1413
#8  0x000000000043f206 in DesktopView::event (this=0x202efd0, e=0x7fffda1d6fd0) at /build/plasma-workspace-kxRFE_/plasma-workspace-5.5.5.2/shell/desktopview.cpp:205
#9  0x00007f9926c7b05c in QApplicationPrivate::notify_helper (this=this@entry=0x1960c80, receiver=receiver@entry=0x202efd0, e=e@entry=0x7fffda1d6fd0) at kernel/qapplication.cpp:3716
#10 0x00007f9926c80516 in QApplication::notify (this=0x7fffda1d73f0, receiver=0x202efd0, e=0x7fffda1d6fd0) at kernel/qapplication.cpp:3499
#11 0x00007f992617862b in QCoreApplication::notifyInternal (this=0x7fffda1d73f0, receiver=receiver@entry=0x202efd0, event=event@entry=0x7fffda1d6fd0) at kernel/qcoreapplication.cpp:965
#12 0x00007f99264bb4ec in QCoreApplication::sendSpontaneousEvent (event=0x7fffda1d6fd0, receiver=0x202efd0) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:227
#13 QGuiApplicationPrivate::processExposeEvent (e=0x208c5f0) at kernel/qguiapplication.cpp:2663
#14 0x00007f99264bc25d in QGuiApplicationPrivate::processWindowSystemEvent (e=e@entry=0x208c5f0) at kernel/qguiapplication.cpp:1658
#15 0x00007f992649ff38 in QWindowSystemInterface::sendWindowSystemEvents (flags=...) at kernel/qwindowsysteminterface.cpp:625
#16 0x00007f9919b9c070 in userEventSourceDispatch (source=<optimized out>) at eventdispatchers/qeventdispatcher_glib.cpp:70
#17 0x00007f9922637127 in g_main_context_dispatch () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#18 0x00007f9922637380 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#19 0x00007f992263742c in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#20 0x00007f99261cea7f in QEventDispatcherGlib::processEvents (this=0x19a0e00, flags=...) at kernel/qeventdispatcher_glib.cpp:418
#21 0x00007f9926175dea in QEventLoop::exec (this=this@entry=0x7fffda1d7290, flags=..., flags@entry=...) at kernel/qeventloop.cpp:204
#22 0x00007f992617de8c in QCoreApplication::exec () at kernel/qcoreapplication.cpp:1229
#23 0x00007f99264b1c3c in QGuiApplication::exec () at kernel/qguiapplication.cpp:1542
#24 0x00007f9926c77495 in QApplication::exec () at kernel/qapplication.cpp:2976
#25 0x0000000000432d4a in main (argc=4, argv=<optimized out>) at /build/plasma-workspace-kxRFE_/plasma-workspace-5.5.5.2/shell/main.cpp:181

Possible duplicates by query: bug 363884, bug 363388, bug 363386, bug 363035, bug 362980.

Reported using DrKonqi