Just after I logged in and splash screen disappears plasma crashes immediately. I just see black screen and a mouse cursor. Plasma tries to restart but crashes again and again in endless loop

Application: plasmashell (5.6.2)

Qt Version: 5.5.1
Frameworks Version: 5.21.0
Operating System: Linux 4.1.15-gentoo-r1 x86_64
Distribution (Platform): Gentoo Packages

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 0x7f1da3795740 (LWP 3359))]

Thread 6 (Thread 0x7f1d9210d700 (LWP 3360)):
#0  0x00007f1d9e03f23d in poll () from /lib64/libc.so.6
#1  0x00007f1da1f4ca9a in ?? () from /usr/lib64/libxcb.so.1
#2  0x00007f1da1f4e7b7 in xcb_wait_for_event () from /usr/lib64/libxcb.so.1
#3  0x00007f1d9488b9e9 in ?? () from /usr/lib64/libQt5XcbQpa.so.5
#4  0x00007f1d9e6a69b3 in ?? () from /usr/lib64/libQt5Core.so.5
#5  0x00007f1d9d84b456 in start_thread () from /lib64/libpthread.so.0
#6  0x00007f1d9e04834d in clone () from /lib64/libc.so.6

Thread 5 (Thread 0x7f1d8b3ea700 (LWP 3365)):
#0  0x00007f1d9a109dbb in ?? () from /usr/lib64/libglib-2.0.so.0
#1  0x00007f1d9a10c28b in g_main_context_prepare () from /usr/lib64/libglib-2.0.so.0
#2  0x00007f1d9a10cb90 in ?? () from /usr/lib64/libglib-2.0.so.0
#3  0x00007f1d9a10cd84 in g_main_context_iteration () from /usr/lib64/libglib-2.0.so.0
#4  0x00007f1d9e890e63 in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib64/libQt5Core.so.5
#5  0x00007f1d9e845d5b in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib64/libQt5Core.so.5
#6  0x00007f1d9e6a20ca in QThread::exec() () from /usr/lib64/libQt5Core.so.5
#7  0x00007f1da0e18840 in ?? () from /usr/lib64/libQt5Qml.so.5
#8  0x00007f1d9e6a69b3 in ?? () from /usr/lib64/libQt5Core.so.5
#9  0x00007f1d9d84b456 in start_thread () from /lib64/libpthread.so.0
#10 0x00007f1d9e04834d in clone () from /lib64/libc.so.6

Thread 4 (Thread 0x7f1d802fc700 (LWP 3366)):
#0  0x00007f1d9a109e37 in ?? () from /usr/lib64/libglib-2.0.so.0
#1  0x00007f1d9a10c28b in g_main_context_prepare () from /usr/lib64/libglib-2.0.so.0
#2  0x00007f1d9a10cb90 in ?? () from /usr/lib64/libglib-2.0.so.0
#3  0x00007f1d9a10cd84 in g_main_context_iteration () from /usr/lib64/libglib-2.0.so.0
#4  0x00007f1d9e890e63 in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib64/libQt5Core.so.5
#5  0x00007f1d9e845d5b in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib64/libQt5Core.so.5
#6  0x00007f1d9e6a20ca in QThread::exec() () from /usr/lib64/libQt5Core.so.5
#7  0x00007f1da0e18840 in ?? () from /usr/lib64/libQt5Qml.so.5
#8  0x00007f1d9e6a69b3 in ?? () from /usr/lib64/libQt5Core.so.5
#9  0x00007f1d9d84b456 in start_thread () from /lib64/libpthread.so.0
#10 0x00007f1d9e04834d in clone () from /lib64/libc.so.6

Thread 3 (Thread 0x7f1d7e374700 (LWP 3367)):
#0  0x00007f1d9a10c232 in g_main_context_prepare () from /usr/lib64/libglib-2.0.so.0
#1  0x00007f1d9a10cb90 in ?? () from /usr/lib64/libglib-2.0.so.0
#2  0x00007f1d9a10cd84 in g_main_context_iteration () from /usr/lib64/libglib-2.0.so.0
#3  0x00007f1d9e890e63 in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib64/libQt5Core.so.5
#4  0x00007f1d9e845d5b in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib64/libQt5Core.so.5
#5  0x00007f1d9e6a20ca in QThread::exec() () from /usr/lib64/libQt5Core.so.5
#6  0x00007f1da0e18840 in ?? () from /usr/lib64/libQt5Qml.so.5
#7  0x00007f1d9e6a69b3 in ?? () from /usr/lib64/libQt5Core.so.5
#8  0x00007f1d9d84b456 in start_thread () from /lib64/libpthread.so.0
#9  0x00007f1d9e04834d in clone () from /lib64/libc.so.6

Thread 2 (Thread 0x7f1d7ca10700 (LWP 3368)):
#0  0x00007f1d9d850fcf in pthread_cond_wait@@GLIBC_2.3.2 () from /lib64/libpthread.so.0
#1  0x00007f1da31d8e5b in ?? () from /usr/lib64/libQt5Script.so.5
#2  0x00007f1da31d8e89 in ?? () from /usr/lib64/libQt5Script.so.5
#3  0x00007f1d9d84b456 in start_thread () from /lib64/libpthread.so.0
#4  0x00007f1d9e04834d in clone () from /lib64/libc.so.6

Thread 1 (Thread 0x7f1da3795740 (LWP 3359)):
[KCrash Handler]
#6  0x00007f1d9e8710b1 in QObjectPrivate::addConnection(int, QObjectPrivate::Connection*) () from /usr/lib64/libQt5Core.so.5
#7  0x00007f1d9e873503 in QObjectPrivate::connectImpl(QObject const*, int, QObject const*, void**, QtPrivate::QSlotObjectBase*, Qt::ConnectionType, int const*, QMetaObject const*) () from /usr/lib64/libQt5Core.so.5
#8  0x00007f1d9e8738b4 in QObject::connectImpl(QObject const*, void**, QObject const*, void**, QtPrivate::QSlotObjectBase*, Qt::ConnectionType, int const*, QMetaObject const*) () from /usr/lib64/libQt5Core.so.5
#9  0x00007f1d77bec039 in ?? () from /usr/lib64/qt5/qml/org/kde/plasma/activityswitcher/libactivityswitcherextensionplugin.so
#10 0x00007f1d77bec769 in ?? () from /usr/lib64/qt5/qml/org/kde/plasma/activityswitcher/libactivityswitcherextensionplugin.so
#11 0x00007f1d77beca51 in ?? () from /usr/lib64/qt5/qml/org/kde/plasma/activityswitcher/libactivityswitcherextensionplugin.so
#12 0x00007f1d77becc58 in ?? () from /usr/lib64/qt5/qml/org/kde/plasma/activityswitcher/libactivityswitcherextensionplugin.so
#13 0x00007f1d77bed13f in KActivitiesBackport::ActivitiesModel::ActivitiesModel(QVector<KActivities::Info::State>, QObject*) () from /usr/lib64/qt5/qml/org/kde/plasma/activityswitcher/libactivityswitcherextensionplugin.so
#14 0x00007f1d77be7d33 in ?? () from /usr/lib64/qt5/qml/org/kde/plasma/activityswitcher/libactivityswitcherextensionplugin.so
#15 0x00007f1d77be2287 in ?? () from /usr/lib64/qt5/qml/org/kde/plasma/activityswitcher/libactivityswitcherextensionplugin.so
#16 0x00007f1d77be2ead in ?? () from /usr/lib64/qt5/qml/org/kde/plasma/activityswitcher/libactivityswitcherextensionplugin.so
#17 0x00007f1da0db1d71 in QQmlType::SingletonInstanceInfo::init(QQmlEngine*) () from /usr/lib64/libQt5Qml.so.5
#18 0x00007f1da0e0bcdc in QV4::QmlTypeWrapper::toVariant() const () from /usr/lib64/libQt5Qml.so.5
#19 0x00007f1da0cdb8d9 in ?? () from /usr/lib64/libQt5Qml.so.5
#20 0x00007f1da0cdba60 in QV4::ExecutionEngine::toVariant(QV4::Value const&, int, bool) () from /usr/lib64/libQt5Qml.so.5
#21 0x00007f1da0d9a13e in QQmlPropertyPrivate::writeBinding(QObject*, QQmlPropertyData const&, QQmlContextData*, QQmlJavaScriptExpression*, QV4::Value const&, bool, QFlags<QQmlPropertyPrivate::WriteFlag>) () from /usr/lib64/libQt5Qml.so.5
#22 0x00007f1da0e04edb in QQmlBinding::update(QFlags<QQmlPropertyPrivate::WriteFlag>) () from /usr/lib64/libQt5Qml.so.5
#23 0x00007f1da0e0efaa in ?? () from /usr/lib64/libQt5Qml.so.5
#24 0x00007f1da0da09fa in ?? () from /usr/lib64/libQt5Qml.so.5
#25 0x00007f1da0da1516 in QQmlIncubationController::incubateFor(int) () from /usr/lib64/libQt5Qml.so.5
#26 0x00007f1da1a7f384 in ?? () from /usr/lib64/libKF5Declarative.so.5
#27 0x00007f1da0da11c3 in QQmlEnginePrivate::incubate(QQmlIncubator&, QQmlContextData*) () from /usr/lib64/libQt5Qml.so.5
#28 0x00007f1da0d9caac in QQmlComponent::create(QQmlIncubator&, QQmlContext*, QQmlContext*) () from /usr/lib64/libQt5Qml.so.5
#29 0x00007f1da1a7b853 in KDeclarative::QmlObject::completeInitialization(QHash<QString, QVariant> const&) () from /usr/lib64/libKF5Declarative.so.5
#30 0x00007f1da1a7b93c in ?? () from /usr/lib64/libKF5Declarative.so.5
#31 0x00007f1da1a7bb29 in ?? () from /usr/lib64/libKF5Declarative.so.5
#32 0x00007f1da2722d89 in KQuickAddons::QuickViewSharedEngine::setSource(QUrl const&) () from /usr/lib64/libKF5QuickAddons.so.5
#33 0x0000000000426f56 in ?? ()
#34 0x000000000043e3bc in ?? ()
#35 0x000000000044262f in ?? ()
#36 0x0000000000442d53 in ?? ()
#37 0x00007f1d9e86d212 in QMetaObject::activate(QObject*, int, int, void**) () from /usr/lib64/libQt5Core.so.5
#38 0x00007f1da295639f in KScreen::ConfigOperation::finished(KScreen::ConfigOperation*) () from /usr/lib64/libKF5Screen.so.7
#39 0x00007f1da29428c0 in ?? () from /usr/lib64/libKF5Screen.so.7
#40 0x00007f1d9e86e83e in QObject::event(QEvent*) () from /usr/lib64/libQt5Core.so.5
#41 0x00007f1d9f062b1c in QApplicationPrivate::notify_helper(QObject*, QEvent*) () from /usr/lib64/libQt5Widgets.so.5
#42 0x00007f1d9f067a10 in QApplication::notify(QObject*, QEvent*) () from /usr/lib64/libQt5Widgets.so.5
#43 0x00007f1d9e847134 in QCoreApplication::notifyInternal(QObject*, QEvent*) () from /usr/lib64/libQt5Core.so.5
#44 0x00007f1d9e84974e in QCoreApplicationPrivate::sendPostedEvents(QObject*, int, QThreadData*) () from /usr/lib64/libQt5Core.so.5
#45 0x00007f1d9e8911a3 in ?? () from /usr/lib64/libQt5Core.so.5
#46 0x00007f1d9a10ca9b in g_main_context_dispatch () from /usr/lib64/libglib-2.0.so.0
#47 0x00007f1d9a10ccd0 in ?? () from /usr/lib64/libglib-2.0.so.0
#48 0x00007f1d9a10cd84 in g_main_context_iteration () from /usr/lib64/libglib-2.0.so.0
#49 0x00007f1d9e890e4a in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib64/libQt5Core.so.5
#50 0x00007f1d9e845d5b in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib64/libQt5Core.so.5
#51 0x00007f1d9e84cd54 in QCoreApplication::exec() () from /usr/lib64/libQt5Core.so.5
#52 0x000000000041b691 in ?? ()
#53 0x00007f1d9df7f640 in __libc_start_main () from /lib64/libc.so.6
#54 0x000000000041b7c9 in _start ()


Reproducible: Always

Steps to Reproduce:
1. Log in
2. See how splash screen shows progress while loading
3. See the black screen instead of desktop