Version: (using KDE 4.2.0) OS: Linux Installed from: Debian testing/unstable Packages Sometimes plasma stops updating the desktop (clock stops, plasmoids freeze, taskbar freezes, etc), but event handling of plasmoids still work. After some random usage plasma segfaults. I can't trigger this error, it only happens for me when I'm away from the computer (when I get back, plasma is frozen, and the clock shows the time of freeze - it's some hours after leaving the computer). I've never seen this happening more than once in a session, after automatic plasma restart everything works fine. Sometimes this happens every day, sometimes it's OK for a week. It only segfaults after I do something, I've never found a crash report when I got back. Here is the backtrace of the last crash: Application: Plasma Workspace (plasma), signal SIGSEGV 0x00007f44cd077b51 in nanosleep () from /lib/libc.so.6 [Current thread is 1 (Thread 0x7f44cd677790 (LWP 4923))] Thread 5 (Thread 0x7f44ae779950 (LWP 4924)): #0 0x00007f44cd0a0d62 in select () from /lib/libc.so.6 #1 0x00007f44ca453756 in QProcessManager::run (this=0x21747d0) at io/qprocess_unix.cpp:301 #2 0x00007f44ca38b162 in QThreadPrivate::start (arg=0x21747d0) at thread/qthread_unix.cpp:185 #3 0x00007f44c6052faa in start_thread () from /lib/libpthread.so.0 #4 0x00007f44cd0a750d in clone () from /lib/libc.so.6 #5 0x0000000000000000 in ?? () Thread 4 (Thread 0x7f44ad499950 (LWP 4926)): #0 0x00007f44c6056c09 in pthread_cond_wait@@GLIBC_2.3.2 () from /lib/libpthread.so.0 #1 0x00007f44ca38c159 in QWaitCondition::wait (this=0x2ba1630, mutex=0x2ba1628, time=18446744073709551615) at thread/qwaitcondition_unix.cpp:82 #2 0x00007f44c7a59f4c in QHostInfoAgent::run (this=0x2ba1610) at kernel/qhostinfo.cpp:241 #3 0x00007f44ca38b162 in QThreadPrivate::start (arg=0x2ba1610) at thread/qthread_unix.cpp:185 #4 0x00007f44c6052faa in start_thread () from /lib/libpthread.so.0 #5 0x00007f44cd0a750d in clone () from /lib/libc.so.6 #6 0x0000000000000000 in ?? () Thread 3 (Thread 0x7f44ac464950 (LWP 4927)): #0 0x00007f44c6056c09 in pthread_cond_wait@@GLIBC_2.3.2 () from /lib/libpthread.so.0 #1 0x00007f44ca38c159 in QWaitCondition::wait (this=0x2320bf0, mutex=0x2320be8, time=18446744073709551615) at thread/qwaitcondition_unix.cpp:82 #2 0x00007f44b23e96f0 in RenderThread::run (this=0x2320bd8) at ../../../../plasma/wallpapers/image/renderthread.cpp:91 #3 0x00007f44ca38b162 in QThreadPrivate::start (arg=0x2320bd8) at thread/qthread_unix.cpp:185 #4 0x00007f44c6052faa in start_thread () from /lib/libpthread.so.0 #5 0x00007f44cd0a750d in clone () from /lib/libc.so.6 #6 0x0000000000000000 in ?? () Thread 2 (Thread 0x7f44abc63950 (LWP 4928)): #0 0x00007f44c6056c09 in pthread_cond_wait@@GLIBC_2.3.2 () from /lib/libpthread.so.0 #1 0x00007f44ca38c159 in QWaitCondition::wait (this=0x262de30, mutex=0x262de28, time=18446744073709551615) at thread/qwaitcondition_unix.cpp:82 #2 0x00007f44b23e96f0 in RenderThread::run (this=0x262de18) at ../../../../plasma/wallpapers/image/renderthread.cpp:91 #3 0x00007f44ca38b162 in QThreadPrivate::start (arg=0x262de18) at thread/qthread_unix.cpp:185 #4 0x00007f44c6052faa in start_thread () from /lib/libpthread.so.0 #5 0x00007f44cd0a750d in clone () from /lib/libc.so.6 #6 0x0000000000000000 in ?? () Thread 1 (Thread 0x7f44cd677790 (LWP 4923)): [KCrash Handler] #5 0x0000000000000000 in ?? () #6 0x00007f44cad17f64 in blend_src_generic<RegularSpans> (count=<value optimized out>, spans=0x7fffd57c2640, userData=<value optimized out>) at painting/qdrawhelper.cpp:3180 #7 0x00007f44cad182ce in blend_transformed_argb<RegularSpans> (count=-713309120, spans=0x7fffd57c0440, userData=0x3280c68) at painting/qdrawhelper.cpp:5679 #8 0x00007f44cacdc24f in QRasterizer::rasterize (this=0x3280e28, path=@0x7fffd57c2fe0, fillRule=<value optimized out>) at painting/qrasterizer.cpp:101 #9 0x00007f44cacfde84 in QRasterPaintEngine::fillPath (this=<value optimized out>, path=@0x7fffd57c33f0, fillData=<value optimized out>) at painting/qpaintengine_raster.cpp:1622 #10 0x00007f44cacff48c in QRasterPaintEngine::drawPath (this=0x2f991f0, path=@0x7fffd57c33f0) at painting/qpaintengine_raster.cpp:1866 #11 0x00007f44cac91cb3 in QPainterPrivate::draw_helper (this=0x34ebef0, originalPath=@0x7fffd57c33f0, op=QPainterPrivate::FillDraw) at painting/qpainter.cpp:358 #12 0x00007f44cac943e7 in QPainter::drawRects (this=<value optimized out>, rects=<value optimized out>, rectCount=1) at painting/qpainter.cpp:2955 #13 0x00007f44cac95e18 in QPainter::drawPixmap (this=0x7fffd57c3850, r=<value optimized out>, pm=@0x7fffd57c3670, sr=<value optimized out>) at ../../include/QtGui/../../src/gui/painting/qpainter.h:576 #14 0x00007f44c19b66e2 in OxygenHelper::renderWindowBackground (this=0x21f8ce0, p=0x7fffd57c3850, clipRect=@0x7fffd57c3800, widget=<value optimized out>, pal=<value optimized out>, y_shift=-23) at /usr/include/qt4/QtGui/qpainter.h:750 #15 0x00007f44c19c2e5e in OxygenStyle::eventFilter (this=0x21b3fc0, obj=0x26fed30, ev=0x7fffd57c3f30) at ../../../kstyles/oxygen/oxygen.cpp:3484 #16 0x00007f44ca472668 in QCoreApplicationPrivate::sendThroughObjectEventFilters (this=<value optimized out>, receiver=0x26fed30, event=0x7fffd57c3f30) at kernel/qcoreapplication.cpp:694 #17 0x00007f44cab94a2c in QApplicationPrivate::notify_helper (this=0x21710b0, receiver=0x26fed30, e=0x7fffd57c3f30) at kernel/qapplication.cpp:3799 #18 0x00007f44cab9c7da in QApplication::notify (this=0x214c110, receiver=0x26fed30, e=0x7fffd57c3f30) at kernel/qapplication.cpp:3768 #19 0x00007f44cbba9fab in KApplication::notify (this=0x214c110, receiver=0x26fed30, event=0x7fffd57c3f30) at ../../kdeui/kernel/kapplication.cpp:307 #20 0x00007f44ca473391 in QCoreApplication::notifyInternal (this=0x214c110, receiver=0x26fed30, event=0x7fffd57c3f30) at kernel/qcoreapplication.cpp:587 #21 0x00007f44cabe595f in QWidgetPrivate::drawWidget (this=0x2bd0b80, pdev=0x29d7a58, rgn=@0x7fffd57c4230, offset=@0x2bab0f8, flags=5, sharedPainter=0x3229310) at kernel/qwidget.cpp:4636 #22 0x00007f44cad3e724 in QWidgetBackingStore::cleanRegion (this=0x2bab0e0, rgn=@0x7fffd57c4280, widget=0x26fed30, recursiveCopyToScreen=true) at painting/qbackingstore.cpp:1039 #23 0x00007f44cad3eb09 in qt_syncBackingStore (rgn=<value optimized out>, widget=0x26fed30) at painting/qbackingstore.cpp:239 #24 0x00007f44cabf23f2 in QETWidget::translatePaintEvent (this=0x26fed30, event=<value optimized out>) at kernel/qapplication_x11.cpp:4630 #25 0x00007f44cabff325 in QApplication::x11ProcessEvent (this=0x214c110, event=0x7fffd57c4b70) at kernel/qapplication_x11.cpp:3062 #26 0x00007f44cac26cb4 in x11EventSourceDispatch (s=0x21746a0, callback=0, user_data=0x0) at kernel/qguieventdispatcher_glib.cpp:142 #27 0x00007f44c62a0aab in IA__g_main_context_dispatch (context=0x2173930) at /tmp/buildd/glib2.0-2.18.4/glib/gmain.c:2144 #28 0x00007f44c62a426d in g_main_context_iterate (context=0x2173930, block=1, dispatch=1, self=<value optimized out>) at /tmp/buildd/glib2.0-2.18.4/glib/gmain.c:2778 #29 0x00007f44c62a442b in IA__g_main_context_iteration (context=0x2173930, may_block=1) at /tmp/buildd/glib2.0-2.18.4/glib/gmain.c:2841 #30 0x00007f44ca49b71f in QEventDispatcherGlib::processEvents (this=0x2168be0, flags=<value optimized out>) at kernel/qeventdispatcher_glib.cpp:319 #31 0x00007f44cac2647f in QGuiEventDispatcherGlib::processEvents (this=0x7fffd57bc440, flags=<value optimized out>) at kernel/qguieventdispatcher_glib.cpp:198 #32 0x00007f44ca471cb2 in QEventLoop::processEvents (this=<value optimized out>, flags={i = -713273760}) at kernel/qeventloop.cpp:143 #33 0x00007f44ca471e3d in QEventLoop::exec (this=0x7fffd57c4ea0, flags={i = -713273680}) at kernel/qeventloop.cpp:194 #34 0x00007f44ca4742ed in QCoreApplication::exec () at kernel/qcoreapplication.cpp:845 #35 0x00007f44cd36551b in kdemain (argc=1, argv=0x7fffd57c51a8) at ../../../../plasma/shells/desktop/main.cpp:54 #36 0x00007f44ccff75a6 in __libc_start_main () from /lib/libc.so.6 #37 0x0000000000400629 in _start () My report may be related to Bug #175087 (http://bugs.kde.org/show_bug.cgi?id=175087), but I've only experienced this in KDE 4.2.0.
The crash seems similar to the one in bug 176014 / bug 182482
(In reply to comment #1) I will keep an eye on the backtraces if this happens again to see whether the segfault happens at the same place. (Since my report I haven't experienced this problem yet.)
I've just had the freeze and crash again. I was just browsing around on the internet, I didn't do anything special - see the diary of my session below. This time I wasn't away from the computer. Detailed symptoms (in addition to the original report): - KGet's "play" icon (which shows that something is being downloaded) still blinks (in system tray) - hovering on taskbar entries shows window previews, but in a small size without title and icon, and instead of a black background a semi-transparent white background is drawn. (I attach the complete screenshot of the frozen state with hovering on Kontact's entry - the preview's background is not shown /I don't know, why; maybe 1 second delay was too short/, and a screenshot of a normal preview). - the taskbar works: the position of the entries (eg. clicking or hovering on them) is according to the real situation, not the frozen one - after some time, plasma segfaults (the backtrace is the same as the one I've already reported - I can copy the new one too, if needed) I _think_ that the segfault comes only when I interact with Plasma, because of the following: I've only noticed the freeze after ~five minutes since it had happened, then I started hovering and clicking on the taskbar, then I started KSnapshot with KRunner (Alt+F2), and some seconds later the segfault happened (I assume that taking the screenshot is unrelated to the crash). Since login, I did the following: - launch Kontact - ~10 hours away (DPMS standby after 10 minutes) - launch Konqueror, some browsing - ~3 hours away - some browsing (including flash videos, Macromedia Player 10, amd64) - launch Krusader - open an audio file with MPlayer from Krusader - browsing - close MPlayer - browsing - plasma freeze happened somewhere here - browsing - open another audio file with MPLayer from Krusader - browsing - noticing the freeze I hope these details help to locate the problem.
Created attachment 31420 [details] Screenshot of the desktop with frozen plasma, with abnormally small preview
Created attachment 31421 [details] Screenshot of "regular" window preview
Now the freeze and crash happened again. I wanted to launch Konqeror (but K menu wasn't working), so I called KLaunch with Alt+F2, and soon it has crashed (with basically the same backtrace) - but for the second time it worked. I have these lines in my ~/.xsession-errors that may be relevant (and start to appear from the time of freezing, and disappear after the crash): QPainter::begin: Paint device returned engine == 0, type: 3 QPainter::setCompositionMode: Painter not active QPainter::end: Painter not active, aborted and I have some of these, too (maybe unrelated, because it is in the logs also before and after the freeze): kwin: X Error (error: <unknown>[DAMAGE+0], request: XDamageDestroy[DAMAGE+2], resource: 0x141467f) The backtrace of plasma is now different: Application: Plasma Workspace (plasma), signal SIGSEGV 0x00007f523d7398d1 in nanosleep () from /lib/libc.so.6 Current language: auto; currently c [Current thread is 1 (Thread 0x7f523dd39790 (LWP 4902))] Thread 4 (Thread 0x7f521db39950 (LWP 4906)): #0 pthread_cond_wait@@GLIBC_2.3.2 () at ../nptl/sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:261 #1 0x00007f523aa4e159 in QWaitCondition::wait (this=0x1e215c0, mutex=0x1e215b8, time=18446744073709551615) at thread/qwaitcondition_unix.cpp:82 #2 0x00007f523811bf4c in QHostInfoAgent::run (this=0x1e215a0) at kernel/qhostinfo.cpp:241 #3 0x00007f523aa4d162 in QThreadPrivate::start (arg=0x1e215a0) at thread/qthread_unix.cpp:185 #4 0x00007f5236713faa in start_thread (arg=<value optimized out>) at pthread_create.c:297 #5 0x00007f523d7692ed in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:112 #6 0x0000000000000000 in ?? () Thread 3 (Thread 0x7f521cb04950 (LWP 4907)): #0 pthread_cond_wait@@GLIBC_2.3.2 () at ../nptl/sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:261 #1 0x00007f523aa4e159 in QWaitCondition::wait (this=0x15c0c50, mutex=0x15c0c48, time=18446744073709551615) at thread/qwaitcondition_unix.cpp:82 #2 0x00007f5222a896f0 in RenderThread::run (this=0x15c0c38) at ../../../../plasma/wallpapers/image/renderthread.cpp:91 #3 0x00007f523aa4d162 in QThreadPrivate::start (arg=0x15c0c38) at thread/qthread_unix.cpp:185 #4 0x00007f5236713faa in start_thread (arg=<value optimized out>) at pthread_create.c:297 #5 0x00007f523d7692ed in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:112 #6 0x0000000000000000 in ?? () Current language: auto; currently asm Thread 2 (Thread 0x7f521c303950 (LWP 4908)): #0 pthread_cond_wait@@GLIBC_2.3.2 () at ../nptl/sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:261 #1 0x00007f523aa4e159 in QWaitCondition::wait (this=0x18d63e0, mutex=0x18d63d8, time=18446744073709551615) at thread/qwaitcondition_unix.cpp:82 #2 0x00007f5222a896f0 in RenderThread::run (this=0x18d63c8) at ../../../../plasma/wallpapers/image/renderthread.cpp:91 #3 0x00007f523aa4d162 in QThreadPrivate::start (arg=0x18d63c8) at thread/qthread_unix.cpp:185 #4 0x00007f5236713faa in start_thread (arg=<value optimized out>) at pthread_create.c:297 #5 0x00007f523d7692ed in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:112 #6 0x0000000000000000 in ?? () Thread 1 (Thread 0x7f523dd39790 (LWP 4902)): [KCrash Handler] #5 0x00007f523cac4100 in XVisualIDFromVisual () from /usr/lib/libX11.so.6 #6 0x00007f523b2dc599 in QWidgetPrivate::create_sys (this=0x2452a60, window=32315596, initializeWindow=true, destroyOldWindow=true) at kernel/qwidget_x11.cpp:528 #7 0x00007f523b2a6a82 in QWidget::create (this=0x2166b00, window=32315596, initializeWindow=176, destroyOldWindow=true) at kernel/qwidget.cpp:1236 #8 0x00007f522045c279 in SystemTray::X11EmbedContainer::embedSystemTrayClient (this=0x2166b00, clientId=59548355) at ../../../../plasma/applets/systemtray/protocols/fdo/x11embedcontainer.cpp:112 #9 0x00007f5220458532 in SystemTray::FdoGraphicsWidget::setupXEmbedDelegate (this=<value optimized out>) at ../../../../plasma/applets/systemtray/protocols/fdo/fdographicswidget.cpp:158 #10 0x00007f52204585f0 in SystemTray::FdoGraphicsWidget::qt_metacall (this=0x2042d60, _c=QMetaObject::InvokeMetaMethod, _id=<value optimized out>, _a=<value optimized out>) at ./fdographicswidget.moc:77 #11 0x00007f523ab496e4 in QMetaObject::activate (sender=0x22deab0, from_signal_index=<value optimized out>, to_signal_index=4, argv=0x1) at kernel/qobject.cpp:3031 #12 0x00007f523ab4f94f in QSingleShotTimer::timerEvent (this=0x22deab0) at kernel/qtimer.cpp:294 #13 0x00007f523ab43ff3 in QObject::event (this=0x22deab0, e=0x7fff45e84b50) at kernel/qobject.cpp:1120 #14 0x00007f523b256a5d in QApplicationPrivate::notify_helper (this=0x14010b0, receiver=0x22deab0, e=0x7fff45e85670) at kernel/qapplication.cpp:3803 #15 0x00007f523b25e7da in QApplication::notify (this=0x13dc110, receiver=0x22deab0, e=0x7fff45e85670) at kernel/qapplication.cpp:3768 #16 0x00007f523c26bfab in KApplication::notify (this=0x13dc110, receiver=0x22deab0, event=0x7fff45e85670) at ../../kdeui/kernel/kapplication.cpp:307 #17 0x00007f523ab35391 in QCoreApplication::notifyInternal (this=0x13dc110, receiver=0x22deab0, event=0x7fff45e85670) at kernel/qcoreapplication.cpp:587 #18 0x00007f523ab61266 in QTimerInfoList::activateTimers (this=0x1404630) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:209 #19 0x00007f523ab5d7bd in timerSourceDispatch (source=<value optimized out>) at kernel/qeventdispatcher_glib.cpp:160 #20 0x00007f5236961afb in IA__g_main_context_dispatch (context=0x1403930) at /build/buildd/glib2.0-2.18.4/glib/gmain.c:2144 #21 0x00007f52369652bd in g_main_context_iterate (context=0x1403930, block=1, dispatch=1, self=<value optimized out>) at /build/buildd/glib2.0-2.18.4/glib/gmain.c:2778 #22 0x00007f523696547b in IA__g_main_context_iteration (context=0x1403930, may_block=1) at /build/buildd/glib2.0-2.18.4/glib/gmain.c:2841 #23 0x00007f523ab5d71f in QEventDispatcherGlib::processEvents (this=0x13f8be0, flags=<value optimized out>) at kernel/qeventdispatcher_glib.cpp:319 #24 0x00007f523b2e847f in QGuiEventDispatcherGlib::processEvents (this=0x0, flags=<value optimized out>) at kernel/qguieventdispatcher_glib.cpp:198 #25 0x00007f523ab33cb2 in QEventLoop::processEvents (this=<value optimized out>, flags={i = 1172855008}) at kernel/qeventloop.cpp:143 #26 0x00007f523ab33e3d in QEventLoop::exec (this=0x7fff45e85920, flags={i = 1172855104}) at kernel/qeventloop.cpp:194 #27 0x00007f523b5eb0f5 in QMenu::exec (this=<value optimized out>, p=@0x7fff45e85a00, action=0x0) at widgets/qmenu.cpp:1938 #28 0x00007f523d360f60 in Plasma::ContainmentPrivate::showContextMenu (this=0x195ac80, point=<value optimized out>, screenPos=@0x7fff45e85a00, includeApplet=true) at ../../plasma/containment.cpp:611 #29 0x00007f523d36106e in Plasma::Containment::contextMenuEvent (this=0x18d6ee0, event=0x7fff45e86090) at ../../plasma/containment.cpp:476 #30 0x00007f523b7703f3 in QGraphicsItem::sceneEvent (this=0x0, event=0x7fff45e84b50) at graphicsview/qgraphicsitem.cpp:3971 #31 0x00007f523b794ab6 in QGraphicsScene::contextMenuEvent (this=<value optimized out>, contextMenuEvent=0x7fff45e86090) at graphicsview/qgraphicsscene.cpp:3109 #32 0x00007f523b797645 in QGraphicsScene::event (this=0x1466850, event=0x7fff45e86090) at graphicsview/qgraphicsscene.cpp:2951 #33 0x00007f523b256a5d in QApplicationPrivate::notify_helper (this=0x14010b0, receiver=0x1466850, e=0x7fff45e86090) at kernel/qapplication.cpp:3803 #34 0x00007f523b25e7da in QApplication::notify (this=0x13dc110, receiver=0x1466850, e=0x7fff45e86090) at kernel/qapplication.cpp:3768 #35 0x00007f523c26bfab in KApplication::notify (this=0x13dc110, receiver=0x1466850, event=0x7fff45e86090) at ../../kdeui/kernel/kapplication.cpp:307 #36 0x00007f523ab35391 in QCoreApplication::notifyInternal (this=0x13dc110, receiver=0x1466850, event=0x7fff45e86090) at kernel/qcoreapplication.cpp:587 #37 0x00007f523b7a2d23 in QGraphicsView::contextMenuEvent (this=0x1ea8840, event=0x7fff45e86940) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:209 #38 0x00007f523b2a93cd in QWidget::event (this=0x1ea8840, event=0x7fff45e86940) at kernel/qwidget.cpp:7320 #39 0x00007f523b7a524b in QGraphicsView::viewportEvent (this=0x1ea8840, event=0x7fff45e86940) at graphicsview/qgraphicsview.cpp:2337 #40 0x00007f523ab34668 in QCoreApplicationPrivate::sendThroughObjectEventFilters (this=<value optimized out>, receiver=0x1ea8b40, event=0x7fff45e86940) at kernel/qcoreapplication.cpp:694 #41 0x00007f523b256a2c in QApplicationPrivate::notify_helper (this=0x14010b0, receiver=0x1ea8b40, e=0x7fff45e86940) at kernel/qapplication.cpp:3799 #42 0x00007f523b25ec6a in QApplication::notify (this=<value optimized out>, receiver=0x1ea8b40, e=0x7fff45e86940) at kernel/qapplication.cpp:3614 #43 0x00007f523c26bfab in KApplication::notify (this=0x13dc110, receiver=0x1ea8b40, event=0x7fff45e86940) at ../../kdeui/kernel/kapplication.cpp:307 #44 0x00007f523ab35391 in QCoreApplication::notifyInternal (this=0x13dc110, receiver=0x1ea8b40, event=0x7fff45e86940) at kernel/qcoreapplication.cpp:587 #45 0x00007f523b2c2f7b in QETWidget::translateMouseEvent (this=0x1ea8840, event=<value optimized out>) at kernel/qapplication_x11.cpp:4050 #46 0x00007f523b2c182f in QApplication::x11ProcessEvent (this=0x1a6, event=0x7fff45e87230) at kernel/qapplication_x11.cpp:3162 #47 0x00007f523b2e8cb4 in x11EventSourceDispatch (s=0x14046a0, callback=0, user_data=0x0) at kernel/qguieventdispatcher_glib.cpp:142 #48 0x00007f5236961afb in IA__g_main_context_dispatch (context=0x1403930) at /build/buildd/glib2.0-2.18.4/glib/gmain.c:2144 #49 0x00007f52369652bd in g_main_context_iterate (context=0x1403930, block=1, dispatch=1, self=<value optimized out>) at /build/buildd/glib2.0-2.18.4/glib/gmain.c:2778 #50 0x00007f523696547b in IA__g_main_context_iteration (context=0x1403930, may_block=1) at /build/buildd/glib2.0-2.18.4/glib/gmain.c:2841 #51 0x00007f523ab5d71f in QEventDispatcherGlib::processEvents (this=0x13f8be0, flags=<value optimized out>) at kernel/qeventdispatcher_glib.cpp:319 #52 0x00007f523b2e847f in QGuiEventDispatcherGlib::processEvents (this=0x0, flags=<value optimized out>) at kernel/qguieventdispatcher_glib.cpp:198 #53 0x00007f523ab33cb2 in QEventLoop::processEvents (this=<value optimized out>, flags={i = 1172862240}) at kernel/qeventloop.cpp:143 #54 0x00007f523ab33e3d in QEventLoop::exec (this=0x7fff45e87560, flags={i = 1172862320}) at kernel/qeventloop.cpp:194 #55 0x00007f523ab362ed in QCoreApplication::exec () at kernel/qcoreapplication.cpp:845 #56 0x00007f523da2751b in kdemain (argc=1, argv=0x7fff45e87868) at ../../../../plasma/shells/desktop/main.cpp:54 #57 0x00007f523d6b95a6 in __libc_start_main (main=0x4006f0 <main>, argc=1, ubp_av=0x7fff45e87868, init=0x400720 <__libc_csu_init>, fini=<value optimized out>, rtld_fini=<value optimized out>, stack_end=0x7fff45e87858) at libc-start.c:222 #58 0x0000000000400629 in _start () Current language: auto; currently c
the second backtrace is a different (but perhaps related) bug, which is also reported (numerous times) *** This bug has been marked as a duplicate of bug 176014 ***