pasting inline
-- Backtrace:
Application: Plasma (plasmashell), signal: Segmentation fault
Using host libthread_db library "/lib/libthread_db.so.1".
[Current thread is 1 (Thread 0xb33ba7c0 (LWP 2388))]

Thread 8 (Thread 0xb1779b40 (LWP 2390)):
#0  0xb77d9e4c in __kernel_vsyscall ()
#1  0xb4f41feb in poll () from /lib/libc.so.6
#2  0xb718b8cd in ?? () from /usr/lib/libxcb.so.1
#3  0xb718d8db in xcb_wait_for_event () from /usr/lib/libxcb.so.1
#4  0xb18e5853 in QXcbEventReader::run (this=0x9fa97e8) at qxcbconnection.cpp:1106
#5  0xb521e970 in QThreadPrivate::start (arg=0x9fa97e8) at thread/qthread_unix.cpp:337
#6  0xb4df9315 in start_thread () from /lib/libpthread.so.0
#7  0xb4f4c3be in clone () from /lib/libc.so.6

Thread 7 (Thread 0xb025bb40 (LWP 2399)):
#0  0xb77d9e4c in __kernel_vsyscall ()
#1  0xb4f3c38b in read () from /lib/libc.so.6
#2  0xb468a3d5 in ?? () from /usr/lib/libglib-2.0.so.0
#3  0xb4645686 in g_main_context_check () from /usr/lib/libglib-2.0.so.0
#4  0xb4645b41 in ?? () from /usr/lib/libglib-2.0.so.0
#5  0xb4645ce4 in g_main_context_iteration () from /usr/lib/libglib-2.0.so.0
#6  0xb543c984 in QEventDispatcherGlib::processEvents (this=0xaf900468, flags=...) at kernel/qeventdispatcher_glib.cpp:420
#7  0xb53e2033 in QEventLoop::processEvents (this=0xb025b218, flags=...) at kernel/qeventloop.cpp:128
#8  0xb53e246a in QEventLoop::exec (this=0xb025b218, flags=...) at kernel/qeventloop.cpp:204
#9  0xb52196b5 in QThread::exec (this=0xa045e18) at thread/qthread.cpp:503
#10 0xb697171f in QQmlThreadPrivate::run (this=0xa045e18) at /usr/src/debug/qtdeclarative-opensource-src-5.4.2/src/qml/qml/ftw/qqmlthread.cpp:141
#11 0xb521e970 in QThreadPrivate::start (arg=0xa045e18) at thread/qthread_unix.cpp:337
#12 0xb4df9315 in start_thread () from /lib/libpthread.so.0
#13 0xb4f4c3be in clone () from /lib/libc.so.6

Thread 6 (Thread 0xab90bb40 (LWP 2400)):
#0  0xb468b7ad in g_mutex_lock () from /usr/lib/libglib-2.0.so.0
#1  0xb46455e2 in g_main_context_check () from /usr/lib/libglib-2.0.so.0
#2  0xb4645b41 in ?? () from /usr/lib/libglib-2.0.so.0
#3  0xb4645ce4 in g_main_context_iteration () from /usr/lib/libglib-2.0.so.0
#4  0xb543c984 in QEventDispatcherGlib::processEvents (this=0xa17c8d8, flags=...) at kernel/qeventdispatcher_glib.cpp:420
#5  0xb53e2033 in QEventLoop::processEvents (this=0xab90b218, flags=...) at kernel/qeventloop.cpp:128
#6  0xb53e246a in QEventLoop::exec (this=0xab90b218, flags=...) at kernel/qeventloop.cpp:204
#7  0xb52196b5 in QThread::exec (this=0xa188c30) at thread/qthread.cpp:503
#8  0xb697171f in QQmlThreadPrivate::run (this=0xa188c30) at /usr/src/debug/qtdeclarative-opensource-src-5.4.2/src/qml/qml/ftw/qqmlthread.cpp:141
#9  0xb521e970 in QThreadPrivate::start (arg=0xa188c30) at thread/qthread_unix.cpp:337
#10 0xb4df9315 in start_thread () from /lib/libpthread.so.0
#11 0xb4f4c3be in clone () from /lib/libc.so.6

Thread 5 (Thread 0xa9d32b40 (LWP 2404)):
#0  0xb468b7d8 in g_mutex_unlock () from /usr/lib/libglib-2.0.so.0
#1  0xb4645aaf in ?? () from /usr/lib/libglib-2.0.so.0
#2  0xb4645ce4 in g_main_context_iteration () from /usr/lib/libglib-2.0.so.0
#3  0xb543c984 in QEventDispatcherGlib::processEvents (this=0xb0e039f0, flags=...) at kernel/qeventdispatcher_glib.cpp:420
#4  0xb53e2033 in QEventLoop::processEvents (this=0xa9d32218, flags=...) at kernel/qeventloop.cpp:128
#5  0xb53e246a in QEventLoop::exec (this=0xa9d32218, flags=...) at kernel/qeventloop.cpp:204
#6  0xb52196b5 in QThread::exec (this=0xa265fc0) at thread/qthread.cpp:503
#7  0xb697171f in QQmlThreadPrivate::run (this=0xa265fc0) at /usr/src/debug/qtdeclarative-opensource-src-5.4.2/src/qml/qml/ftw/qqmlthread.cpp:141
#8  0xb521e970 in QThreadPrivate::start (arg=0xa265fc0) at thread/qthread_unix.cpp:337
#9  0xb4df9315 in start_thread () from /lib/libpthread.so.0
#10 0xb4f4c3be in clone () from /lib/libc.so.6

Thread 4 (Thread 0xa8c2cb40 (LWP 2405)):
#0  0xb77d9e4c in __kernel_vsyscall ()
#1  0xb4dfea2b in pthread_cond_wait@@GLIBC_2.3.2 () from /lib/libpthread.so.0
#2  0xb4f5932d in pthread_cond_wait@@GLIBC_2.3.2 () from /lib/libc.so.6
#3  0xb76112bc in ?? () from /usr/lib/libQt5Script.so.5
#4  0xb76112fc in ?? () from /usr/lib/libQt5Script.so.5
#5  0xb4df9315 in start_thread () from /lib/libpthread.so.0
#6  0xb4f4c3be in clone () from /lib/libc.so.6

Thread 3 (Thread 0xa7612b40 (LWP 2406)):
#0  0xb77d9e4c in __kernel_vsyscall ()
#1  0xb4f3c38b in read () from /lib/libc.so.6
#2  0xb468a3d5 in ?? () from /usr/lib/libglib-2.0.so.0
#3  0xb4645686 in g_main_context_check () from /usr/lib/libglib-2.0.so.0
#4  0xb4645b41 in ?? () from /usr/lib/libglib-2.0.so.0
#5  0xb4645ce4 in g_main_context_iteration () from /usr/lib/libglib-2.0.so.0
#6  0xb543c984 in QEventDispatcherGlib::processEvents (this=0xa4ac0f0, flags=...) at kernel/qeventdispatcher_glib.cpp:420
#7  0xb53e2033 in QEventLoop::processEvents (this=0xa76121d8, flags=...) at kernel/qeventloop.cpp:128
#8  0xb53e246a in QEventLoop::exec (this=0xa76121d8, flags=...) at kernel/qeventloop.cpp:204
#9  0xb52196b5 in QThread::exec (this=0xa438498) at thread/qthread.cpp:503
#10 0xb6d41de9 in QQuickPixmapReader::run (this=0xa438498) at /usr/src/debug/qtdeclarative-opensource-src-5.4.2/src/quick/util/qquickpixmapcache.cpp:714
#11 0xb521e970 in QThreadPrivate::start (arg=0xa438498) at thread/qthread_unix.cpp:337
#12 0xb4df9315 in start_thread () from /lib/libpthread.so.0
#13 0xb4f4c3be in clone () from /lib/libc.so.6

Thread 2 (Thread 0x9feffb40 (LWP 2407)):
#0  0xb77d9838 in ?? ()
#1  0xb77d9bcd in __vdso_clock_gettime ()
#2  0xb4f59e52 in clock_gettime () from /lib/libc.so.6
#3  0xb52b72ac in qt_clock_gettime (ts=0x9fefefa8, clock=<optimized out>) at tools/qelapsedtimer_unix.cpp:105
#4  do_gettime (frac=<synthetic pointer>, sec=<synthetic pointer>) at tools/qelapsedtimer_unix.cpp:161
#5  qt_gettime () at tools/qelapsedtimer_unix.cpp:170
#6  0xb543a411 in QTimerInfoList::updateCurrentTime (this=0xaf9454cc) at kernel/qtimerinfo_unix.cpp:84
#7  0xb543c054 in timerSourceCheckHelper (src=0xaf945498) at kernel/qeventdispatcher_glib.cpp:141
#8  idleTimerSourceCheck (source=0xaf988670) at kernel/qeventdispatcher_glib.cpp:218
#9  0xb46455d2 in g_main_context_check () from /usr/lib/libglib-2.0.so.0
#10 0xb4645b41 in ?? () from /usr/lib/libglib-2.0.so.0
#11 0xb4645ce4 in g_main_context_iteration () from /usr/lib/libglib-2.0.so.0
#12 0xb543c984 in QEventDispatcherGlib::processEvents (this=0xaf9a9d88, flags=...) at kernel/qeventdispatcher_glib.cpp:420
#13 0xb53e2033 in QEventLoop::processEvents (this=0x9feff1f8, flags=...) at kernel/qeventloop.cpp:128
#14 0xb53e246a in QEventLoop::exec (this=0x9feff1f8, flags=...) at kernel/qeventloop.cpp:204
#15 0xb52196b5 in QThread::exec (this=0xabbbae0) at thread/qthread.cpp:503
#16 0xa64ddd44 in KCupsConnection::run() () from /usr/lib/libkcupslib.so
#17 0xb521e970 in QThreadPrivate::start (arg=0xabbbae0) at thread/qthread_unix.cpp:337
#18 0xb4df9315 in start_thread () from /lib/libpthread.so.0
#19 0xb4f4c3be in clone () from /lib/libc.so.6

Thread 1 (Thread 0xb33ba7c0 (LWP 2388)):
[KCrash Handler]
#7  0x0b69f790 in ?? ()
#8  0xb68b08d6 in QV4::MultiplyWrappedQObjectMap::insert (this=0xb166040, key=0xba96290, value=0x9f0afb60) at /usr/src/debug/qtdeclarative-opensource-src-5.4.2/src/qml/jsruntime/qv4qobjectwrapper.cpp:1909
#9  0xb68b0cae in QV4::QObjectWrapper::wrap (engine=0xa2cf868, object=0xba96290) at /usr/src/debug/qtdeclarative-opensource-src-5.4.2/src/qml/jsruntime/qv4qobjectwrapper.cpp:613
#10 0xb69736a5 in QV8Engine::fromVariant (this=0xa265a40, variant=...) at /usr/src/debug/qtdeclarative-opensource-src-5.4.2/src/qml/qml/v8/qv8engine.cpp:404
#11 0xb6964c9c in QV4::QmlContextWrapper::get (m=0xa8cf6530, name=0xa82da9e0, hasProperty=0xbfc343fc) at /usr/src/debug/qtdeclarative-opensource-src-5.4.2/src/qml/qml/qqmlcontextwrapper.cpp:234
#12 0xb68453d9 in get (hasProperty=<optimized out>, name=0xa82da9e0, this=<optimized out>) at /usr/src/debug/qtdeclarative-opensource-src-5.4.2/src/qml/jsruntime/qv4object_p.h:252
#13 QV4::ExecutionContext::getProperty (this=0xbfc34504, name=0xa82da9e0) at /usr/src/debug/qtdeclarative-opensource-src-5.4.2/src/qml/jsruntime/qv4context.cpp:379
#14 0xb68bfccc in QV4::Runtime::getActivationProperty (ctx=0xbfc34504, name=0xa82da9e0) at /usr/src/debug/qtdeclarative-opensource-src-5.4.2/src/qml/jsruntime/qv4runtime.cpp:669
#15 0xa6a6e941 in ?? ()
#16 0xb687402e in QV4::SimpleScriptFunction::call (that=0xa82db040, callData=0xa8d32008) at /usr/src/debug/qtdeclarative-opensource-src-5.4.2/src/qml/jsruntime/qv4functionobject.cpp:511
#17 0xb6958551 in call (d=0xa8d32008, this=<optimized out>) at /usr/src/debug/qtdeclarative-opensource-src-5.4.2/src/qml/jsruntime/qv4object_p.h:278
#18 QQmlJavaScriptExpression::evaluate (this=0xa83a420, context=0xa3954d0, function=..., callData=0xa8d32008, isUndefined=0x0) at /usr/src/debug/qtdeclarative-opensource-src-5.4.2/src/qml/qml/qqmljavascriptexpression.cpp:158
#19 0xb68fdefa in QQmlBoundSignalExpression::evaluate (this=0xa83a410, a=0x0) at /usr/src/debug/qtdeclarative-opensource-src-5.4.2/src/qml/qml/qqmlboundsignal.cpp:281
#20 0xb68fe7fd in QQmlBoundSignal_callback (e=0xa88904c, a=0x0) at /usr/src/debug/qtdeclarative-opensource-src-5.4.2/src/qml/qml/qqmlboundsignal.cpp:408
#21 0xb693be53 in QQmlNotifier::emitNotify (endpoint=0xa88904c, a=0x0) at /usr/src/debug/qtdeclarative-opensource-src-5.4.2/src/qml/qml/qqmlnotifier.cpp:73
#22 0xb68dcb4f in QQmlData::signalEmitted (object=0xa93ab48, index=3, a=0x0) at /usr/src/debug/qtdeclarative-opensource-src-5.4.2/src/qml/qml/qqmlengine.cpp:717
#23 0xb5416062 in QMetaObject::activate (sender=0xa93ab48, signalOffset=3, local_signal_index=0, argv=0x0) at kernel/qobject.cpp:3603
#24 0xb5416d9d in QMetaObject::activate (sender=0xa93ab48, m=0xb6b3f6f4 <QQmlTimer::staticMetaObject>, local_signal_index=0, argv=0x0) at kernel/qobject.cpp:3582
#25 0xb69e0ed2 in QQmlTimer::triggered (this=0xa93ab48) at .moc/moc_qqmltimer_p.cpp:250
#26 0xb69cf15a in QQmlTimer::event (this=0xa93ab48, e=0xc352c10) at /usr/src/debug/qtdeclarative-opensource-src-5.4.2/src/qml/types/qqmltimer.cpp:334
#27 0xb5d3fcba in QApplicationPrivate::notify_helper (this=0x9f94860, receiver=0xa93ab48, e=0xc352c10) at kernel/qapplication.cpp:3720
#28 0xb5d45304 in QApplication::notify (this=0xbfc34e8c, receiver=0xa93ab48, e=0xc352c10) at kernel/qapplication.cpp:3503
#29 0xb53e4ccf in QCoreApplication::notifyInternal (this=0xbfc34e8c, receiver=0xa93ab48, event=0xc352c10) at kernel/qcoreapplication.cpp:935
#30 0xb53e6fc5 in sendEvent (event=0xc352c10, receiver=<optimized out>) at kernel/qcoreapplication.h:228
#31 QCoreApplicationPrivate::sendPostedEvents (receiver=0x0, event_type=0, data=0x9f8e8e0) at kernel/qcoreapplication.cpp:1552
#32 0xb53e74e7 in QCoreApplication::sendPostedEvents (receiver=0x0, event_type=0) at kernel/qcoreapplication.cpp:1410
#33 0xb543c573 in postEventSourceDispatch (s=0x9fbd5a8) at kernel/qeventdispatcher_glib.cpp:271
#34 0xb4645999 in g_main_context_dispatch () from /usr/lib/libglib-2.0.so.0
#35 0xb4645c19 in ?? () from /usr/lib/libglib-2.0.so.0
#36 0xb4645ce4 in g_main_context_iteration () from /usr/lib/libglib-2.0.so.0
#37 0xb543c963 in QEventDispatcherGlib::processEvents (this=0x9fc8838, flags=...) at kernel/qeventdispatcher_glib.cpp:418
#38 0xb19145f1 in QPAEventDispatcherGlib::processEvents (this=0x9fc8838, flags=...) at eventdispatchers/qeventdispatcher_glib.cpp:115
#39 0xb53e2033 in QEventLoop::processEvents (this=0xbfc34dac, flags=...) at kernel/qeventloop.cpp:128
#40 0xb53e246a in QEventLoop::exec (this=0xbfc34dac, flags=...) at kernel/qeventloop.cpp:204
#41 0xb53ea10a in QCoreApplication::exec () at kernel/qcoreapplication.cpp:1188
#42 0xb56f5861 in QGuiApplication::exec () at kernel/qguiapplication.cpp:1507
#43 0xb5d3be94 in QApplication::exec () at kernel/qapplication.cpp:2956
#44 0x08075cc1 in main (argc=4, argv=0xbfc34f74) at /usr/src/debug/plasma-workspace-5.4.0/shell/main.cpp:176

*** Bug 353615 has been marked as a duplicate of this bug. ***

seems to be an old Qt issue

Please reopen if this still happens on Qt 5.5 or more recent