Application: plasma-desktop (4.11.14)
KDE Platform Version: 4.14.3
Qt Version: 4.8.6
Operating System: Linux 3.17.7-300.fc21.x86_64 x86_64
Distribution: "Fedora release 21 (Twenty One)"

-- Information about the crash:
- What I was doing when the application crashed: 
Just did a system restart. Was logging in for the first time and when the desktop was loading, plasma crashed and restarted itself.

The crash can be reproduced every time.

-- Backtrace:
Application: Plasma Desktop Shell (plasma-desktop), signal: Segmentation fault
Using host libthread_db library "/lib64/libthread_db.so.1".
[Current thread is 1 (Thread 0x7ff4839be900 (LWP 3453))]

Thread 4 (Thread 0x7ff46b481700 (LWP 3463)):
#0  0x0000003f3160c590 in pthread_cond_wait@@GLIBC_2.3.2 () from /lib64/libpthread.so.0
#1  0x0000003645d9745a in QTWTF::TCMalloc_PageHeap::scavengerThread() () from /lib64/libQtScript.so.4
#2  0x0000003645d97489 in QTWTF::TCMalloc_PageHeap::runScavengerThread(void*) () from /lib64/libQtScript.so.4
#3  0x0000003f3160752a in start_thread () from /lib64/libpthread.so.0
#4  0x0000003f31b0077d in clone () from /lib64/libc.so.6

Thread 3 (Thread 0x7ff3e670e700 (LWP 3466)):
#0  0x0000003f342494e5 in g_main_context_prepare () from /lib64/libglib-2.0.so.0
#1  0x0000003f34249d4b in g_main_context_iterate.isra () from /lib64/libglib-2.0.so.0
#2  0x0000003f34249f3c in g_main_context_iteration () from /lib64/libglib-2.0.so.0
#3  0x000000363a7b4a3e in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /lib64/libQtCore.so.4
#4  0x000000363a784261 in QEventLoop::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /lib64/libQtCore.so.4
#5  0x000000363a7845c5 in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /lib64/libQtCore.so.4
#6  0x000000363a679b59 in QThread::exec() () from /lib64/libQtCore.so.4
#7  0x000000363a764cc3 in QInotifyFileSystemWatcherEngine::run() () from /lib64/libQtCore.so.4
#8  0x000000363a67c3bf in QThreadPrivate::start(void*) () from /lib64/libQtCore.so.4
#9  0x0000003f3160752a in start_thread () from /lib64/libpthread.so.0
#10 0x0000003f31b0077d in clone () from /lib64/libc.so.6

Thread 2 (Thread 0x7ff3da4f3700 (LWP 5092)):
#0  0x0000003f31af51dd in poll () from /lib64/libc.so.6
#1  0x0000003f34249e24 in g_main_context_iterate.isra () from /lib64/libglib-2.0.so.0
#2  0x0000003f34249f3c in g_main_context_iteration () from /lib64/libglib-2.0.so.0
#3  0x000000363a7b4a3e in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /lib64/libQtCore.so.4
#4  0x000000363a784261 in QEventLoop::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /lib64/libQtCore.so.4
#5  0x000000363a7845c5 in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /lib64/libQtCore.so.4
#6  0x000000363a679b59 in QThread::exec() () from /lib64/libQtCore.so.4
#7  0x000000363a67c3bf in QThreadPrivate::start(void*) () from /lib64/libQtCore.so.4
#8  0x0000003f3160752a in start_thread () from /lib64/libpthread.so.0
#9  0x0000003f31b0077d in clone () from /lib64/libc.so.6

Thread 1 (Thread 0x7ff4839be900 (LWP 3453)):
[KCrash Handler]
#5  0x0000003e0820e01e in KPeople::MetaContact::updateContact(QString const&, KABC::Addressee const&) () from /lib64/libkpeople.so.4
#6  0x0000003e082113b5 in KPeople::PersonsModel::onContactChanged(QString const&, KABC::Addressee const&) () from /lib64/libkpeople.so.4
#7  0x000000363a79a25c in QMetaObject::activate(QObject*, QMetaObject const*, int, void**) () from /lib64/libQtCore.so.4
#8  0x0000003e08219567 in KPeople::AllContactsMonitor::contactChanged(QString const&, KABC::Addressee const&) () from /lib64/libkpeople.so.4
#9  0x00007ff3dbf772aa in AkonadiAllContacts::onItemChanged(Akonadi::Item const&) () from /usr/lib64/kde4/akonadi_kpeople_plugin.so
#10 0x000000363a79a25c in QMetaObject::activate(QObject*, QMetaObject const*, int, void**) () from /lib64/libQtCore.so.4
#11 0x00007ff3e75562d7 in Akonadi::Monitor::itemChanged(Akonadi::Item const&, QSet<QByteArray> const&) () from /lib64/libakonadi-kde.so.4
#12 0x00007ff3e7561426 in Akonadi::MonitorPrivate::emitItemsNotification(Akonadi::NotificationMessageV3 const&, QList<Akonadi::Item> const&, Akonadi::Collection const&, Akonadi::Collection const&) () from /lib64/libakonadi-kde.so.4
#13 0x00007ff3e75629ce in Akonadi::MonitorPrivate::emitNotification(Akonadi::NotificationMessageV3 const&) () from /lib64/libakonadi-kde.so.4
#14 0x00007ff3e755e4d1 in Akonadi::MonitorPrivate::flushPipeline() () from /lib64/libakonadi-kde.so.4
#15 0x00007ff3e755e709 in Akonadi::MonitorPrivate::dataAvailable() () from /lib64/libakonadi-kde.so.4
#16 0x000000363a79a25c in QMetaObject::activate(QObject*, QMetaObject const*, int, void**) () from /lib64/libQtCore.so.4
#17 0x00007ff3e74b1fca in Akonadi::EntityListCache<Akonadi::Item, Akonadi::ItemFetchJob, Akonadi::ItemFetchScope>::processResult(KJob*) () from /lib64/libakonadi-kde.so.4
#18 0x000000363a79a25c in QMetaObject::activate(QObject*, QMetaObject const*, int, void**) () from /lib64/libQtCore.so.4
#19 0x00007ff485216b02 in KJob::result(KJob*) () from /lib64/libkdecore.so.5
#20 0x00007ff485216b50 in KJob::emitResult() () from /lib64/libkdecore.so.5
#21 0x000000363a79e951 in QObject::event(QEvent*) () from /lib64/libQtCore.so.4
#22 0x000000308edc7efc in QApplicationPrivate::notify_helper(QObject*, QEvent*) () from /lib64/libQtGui.so.4
#23 0x000000308edce958 in QApplication::notify(QObject*, QEvent*) () from /lib64/libQtGui.so.4
#24 0x00007ff48581686a in KApplication::notify(QObject*, QEvent*) () from /lib64/libkdeui.so.5
#25 0x000000363a78570d in QCoreApplication::notifyInternal(QObject*, QEvent*) () from /lib64/libQtCore.so.4
#26 0x000000363a7889d1 in QCoreApplicationPrivate::sendPostedEvents(QObject*, int, QThreadData*) () from /lib64/libQtCore.so.4
#27 0x000000363a7b48ae in postEventSourceDispatch(_GSource*, int (*)(void*), void*) () from /lib64/libQtCore.so.4
#28 0x0000003f34249aeb in g_main_context_dispatch () from /lib64/libglib-2.0.so.0
#29 0x0000003f34249e88 in g_main_context_iterate.isra () from /lib64/libglib-2.0.so.0
#30 0x0000003f34249f3c in g_main_context_iteration () from /lib64/libglib-2.0.so.0
#31 0x000000363a7b4a1e in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /lib64/libQtCore.so.4
#32 0x000000308ee6b136 in QGuiEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /lib64/libQtGui.so.4
#33 0x000000363a784261 in QEventLoop::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /lib64/libQtCore.so.4
#34 0x000000363a7845c5 in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /lib64/libQtCore.so.4
#35 0x000000363a789ca9 in QCoreApplication::exec() () from /lib64/libQtCore.so.4
#36 0x0000003e092405fd in kdemain () from /lib64/libkdeinit4_plasma-desktop.so
#37 0x0000003f31a1ffe0 in __libc_start_main () from /lib64/libc.so.6
#38 0x000000000040096e in _start ()

Reported using DrKonqi