Trying to reproduce the sys tray bug following the steps in 
https://bugs.kde.org/show_bug.cgi?id=393630



Thread 1 "plasmashell" received signal SIGSEGV, Segmentation fault.
0x00007ffff1a540e7 in QObject::connect (sender=0x555557af5850, signal=0x7fffb01db728 "2textColorChanged()", receiver=0x555557aedc00, 
    method=0x7fffb01db6c8 "1start()", type=Qt::AutoConnection) at /home/david/projects/qt5/qtbase/src/corelib/kernel/qobject.cpp:2680
warning: Source file is more recent than executable.
2680                     (signal && *signal) ? signal+1 : "(null)",
(gdb) bt
#0  0x00007ffff1a540e7 in QObject::connect(QObject const*, char const*, QObject const*, char const*, Qt::ConnectionType)
    (sender=0x555557af5850, signal=0x7fffb01db728 "2textColorChanged()", receiver=0x555557aedc00, method=0x7fffb01db6c8 "1start()", type=Qt::AutoConnection)
    at /home/david/projects/qt5/qtbase/src/corelib/kernel/qobject.cpp:2680
#1  0x00007fffb01d34f6 in Kirigami::BasicTheme::BasicTheme(QObject*) (this=0x555557e87850, parent=0x555557a408f0)
    at /home/david/projects/kde5/src/frameworks/kirigami/src/libkirigami/basictheme.cpp:85
#2  0x00007fffb01ced6f in Kirigami::PlatformTheme::qmlAttachedProperties(QObject*) (object=0x555557a408f0)
    at /home/david/projects/kde5/src/frameworks/kirigami/src/libkirigami/platformtheme.cpp:723
#3  0x00007fffb03fb8aa in QQmlPrivate::AttachedPropertySelector<Kirigami::PlatformTheme, 1>::attachedProperties(QObject*) (obj=0x555557a408f0)
    at /opt/qt5/include/QtQml/qqmlprivate.h:177
#4  0x00007ffff5d76bed in QtQml::qmlAttachedPropertiesObjectById(int, QObject const*, bool)
    (id=<optimized out>, object=object@entry=0x555557a408f0, create=create@entry=true)
    at /home/david/projects/qt5/qtdeclarative/src/qml/qml/qqmlengine.cpp:1576
#5  0x00007ffff5e273ed in QV4::QQmlTypeWrapper::get(QV4::Managed const*, QV4::String*, bool*) (m=0x7fffe27ad490, name=0x7fffe27ad488, hasProperty=0x0)
    at /home/david/projects/qt5-build/qtbase/include/QtCore/../../../../qt5/qtbase/src/corelib/tools/qscopedpointer.h:138
#6  0x00007ffff5d5167d in QV4::Object::get(QV4::String*, bool*) const (hasProperty=0x0, name=<optimized out>, this=0x7fffe27ad490)
    at ../../include/QtQml/5.11.2/QtQml/private/../../../../../../../qt5/qtdeclarative/src/qml/memory/qv4heap_p.h:101
#7  0x00007ffff5d5167d in QV4::Runtime::method_loadProperty(QV4::ExecutionEngine*, QV4::Value const&, int)
    (engine=engine@entry=0x55555587e240, object=..., nameIndex=<optimized out>)
    at /home/david/projects/qt5/qtdeclarative/src/qml/jsruntime/qv4runtime.cpp:728
#8  0x00007ffff5d3ea3e in QV4::Moth::VME::exec(QV4::FunctionObject const*, QV4::Value const*, QV4::Value const*, int) (fo=<optimized out>, 
    fo@entry=0x7fffffffa351, thisObject=thisObject@entry=0x7fffe27ad410, argv=argv@entry=0x7fffe27ad420, argc=<optimized out>)
    at /home/david/projects/qt5/qtdeclarative/src/qml/jsruntime/qv4vme_moth.cpp:720
#9  0x00007ffff5e1078d in QV4::Moth::VME::exec(QV4::Function*, QV4::Value const*, QV4::Value const*, int, QV4::ExecutionContext const*)
    (context=<optimized out>, argc=<optimized out>, argv=0x7fffe27ad420, thisObject=0x7fffe27ad410, v4Function=0x5555580307d0)
    at ../../include/QtQml/5.11.2/QtQml/private/../../../../../../../qt5/qtdeclarative/src/qml/jsruntime/qv4vme_moth_p.h:72
#10 0x00007ffff5e1078d in QV4::Function::call(QV4::Value const*, QV4::Value const*, int, QV4::ExecutionContext const*)
    (context=<optimized out>, argc=<optimized out>, argv=0x7fffe27ad420, thisObject=0x7fffe27ad410, this=0x5555580307d0)
    at ../../include/QtQml/5.11.2/QtQml/private/../../../../../../../qt5/qtdeclarative/src/qml/jsruntime/qv4function_p.h:72
#11 0x00007ffff5e1078d in QQmlJavaScriptExpression::evaluate(QV4::CallData*, bool*)
    (this=this@entry=0x555557a410e0, callData=callData@entry=0x7fffe27ad3f8, isUndefined=isUndefined@entry=0x7fffffffa45f)
    at /home/david/projects/qt5/qtdeclarative/src/qml/qml/qqmljavascriptexpression.cpp:217
#12 0x00007ffff5e1659e in QQmlBinding::evaluate(bool*) (this=this@entry=0x555557a410e0, isUndefined=isUndefined@entry=0x7fffffffa45f)
    at ../../include/QtQml/5.11.2/QtQml/private/../../../../../../../qt5/qtdeclarative/src/qml/jsruntime/qv4jscall_p.h:94
#13 0x00007ffff5e1d68f in QQmlNonbindingBinding::doUpdate(QQmlJavaScriptExpression::DeleteWatcher const&, QFlags<QQmlPropertyData::WriteFlag>, QV4::Scope&)
    (this=0x555557a410e0, watcher=..., flags=..., scope=...) at /home/david/projects/qt5/qtdeclarative/src/qml/qml/qqmlbinding.cpp:245
#14 0x00007ffff5e19ee4 in QQmlBinding::update(QFlags<QQmlPropertyData::WriteFlag>) (this=this@entry=0x555557a410e0, flags=flags@entry=...)
    at /home/david/projects/qt5/qtdeclarative/src/qml/qml/qqmlbinding.cpp:185
#15 0x00007ffff5e1aeec in QQmlBinding::setEnabled(bool, QFlags<QQmlPropertyData::WriteFlag>) (this=0x555557a410e0, e=<optimized out>, flags=...)
    at /home/david/projects/qt5/qtdeclarative/src/qml/qml/qqmlbinding.cpp:548
#16 0x00007ffff5e2bb16 in QQmlObjectCreator::finalize(QQmlInstantiationInterrupt&) (this=0x5555578b9f10, interrupt=...)
    at /home/david/projects/qt5-build/qtbase/include/QtCore/../../../../qt5/qtbase/src/corelib/tools/qshareddata.h:146
#17 0x00007ffff5d939f9 in QQmlIncubatorPrivate::incubate(QQmlInstantiationInterrupt&) (this=this@entry=0x5555578bc5d0, i=...)
--Type <RET> for more, q to quit, c to continue without paging--
    at /home/david/projects/qt5-build/qtbase/include/QtCore/../../../../qt5/qtbase/src/corelib/tools/qscopedpointer.h:116
#18 0x00007ffff5d93fbb in QQmlEnginePrivate::incubate(QQmlIncubator&, QQmlContextData*)
    (this=this@entry=0x55555587cde0, i=..., forContext=forContext@entry=0x5555571723f0)
    at /home/david/projects/qt5-build/qtbase/include/QtCore/../../../../qt5/qtbase/src/corelib/tools/qshareddata.h:146
#19 0x00007ffff5d8ccc1 in QQmlComponent::create(QQmlIncubator&, QQmlContext*, QQmlContext*)
    (this=<optimized out>, incubator=..., context=<optimized out>, forContext=<optimized out>)
    at /home/david/projects/qt5/qtdeclarative/src/qml/qml/qqmlcomponent.cpp:1063
q#20 0x00007ffff64f50f1 in KDeclarative::QmlObject::createObjectFromComponent(QQmlComponent*, QQmlContext*, QHash<QString, QVariant> const&)
    (this=0x555556cd9220, component=0x555557180c80, context=0x555557180760, initialProperties=...)
    at /home/david/projects/kde5/src/frameworks/kdeclarative/src/kdeclarative/qmlobject.cpp:348
#21 0x00007ffff7d6c3d1 in PlasmaQuick::AppletQuickItemPrivate::createFullRepresentationItem() (this=0x55555716bc30)
    at /home/david/projects/kde5/src/frameworks/plasma-framework/src/plasmaquick/appletquickitem.cpp:255
#22 0x00007ffff7d6c7e0 in PlasmaQuick::AppletQuickItemPrivate::preloadForExpansion() (this=0x55555716bc30)
    at /home/david/projects/kde5/src/frameworks/plasma-framework/src/plasmaquick/appletquickitem.cpp:320

#23 0x00007ffff7d6fdca in PlasmaQuick::AppletQuickItem::setExpanded(bool) (this=0x555556b33920, expanded=true)
    at /home/david/projects/kde5/src/frameworks/plasma-framework/src/plasmaquick/appletquickitem.cpp:835
#24 0x00007ffff7d70bec in PlasmaQuick::AppletQuickItem::qt_static_metacall(QObject*, QMetaObject::Call, int, void**)
    (_o=0x555556b33920, _c=QMetaObject::WriteProperty, _id=7, _a=0x7fffffffab80)
    at src/plasmaquick/KF5PlasmaQuick_autogen/include/moc_appletquickitem.cpp:329
#25 0x00007ffff7d70d76 in PlasmaQuick::AppletQuickItem::qt_metacall(QMetaObject::Call, int, void**)
    (this=0x555556b33920, _c=QMetaObject::WriteProperty, _id=7, _a=0x7fffffffab80)
    at src/plasmaquick/KF5PlasmaQuick_autogen/include/moc_appletquickitem.cpp:374
#26 0x00007fffe134efca in AppletInterface::qt_metacall(QMetaObject::Call, int, void**)
    (this=0x555556b33920, _c=QMetaObject::WriteProperty, _id=49, _a=0x7fffffffab80)
    at src/scriptengines/qml/plasma_appletscript_declarative_autogen/include/moc_appletinterface.cpp:707
#27 0x00007ffff1a28e28 in QMetaObject::metacall(QObject*, QMetaObject::Call, int, void**)
    (object=object@entry=0x555556b33920, cl=cl@entry=QMetaObject::WriteProperty, idx=<optimized out>, argv=argv@entry=0x7fffffffab80)
    at /home/david/projects/qt5/qtbase/src/corelib/kernel/qmetaobject.cpp:301
#28 0x00007ffff5d8a03a in QQmlPropertyData::writeProperty(QObject*, void*, QFlags<QQmlPropertyData::WriteFlag>) const
    (this=this@entry=0x7fffd40c6a88, target=target@entry=0x555556b33920, value=<optimized out>, flags=..., flags@entry=...)
    at ../../include/QtQml/5.11.2/QtQml/private/../../../../../../../qt5/qtdeclarative/src/qml/qml/qqmlpropertycache_p.h:350
#29 0x00007ffff5d8769b in QQmlPropertyPrivate::write(QObject*, QQmlPropertyData const&, QVariant const&, QQmlContextData*, QFlags<QQmlPropertyData::WriteFlag>) (object=object@entry=0x555556b33920, property=..., value=..., context=0x555557194c00, flags=..., flags@entry=...)
    at /home/david/projects/qt5/qtdeclarative/src/qml/qml/qqmlproperty.cpp:1219
#30 0x00007ffff5d2dc87 in QV4::QObjectWrapper::setProperty(QV4::ExecutionEngine*, QObject*, QQmlPropertyData*, QV4::Value const&)
    (engine=engine@entry=0x55555587e240, object=object@entry=0x555556b33920, property=property@entry=0x7fffd40c6a88, value=...)
    at /home/david/projects/qt5-build/qtbase/include/QtCore/../../../../qt5/qtbase/src/corelib/global/qflags.h:121
#31 0x00007ffff5d2ee06 in QV4::QObjectWrapper::setQmlProperty(QV4::ExecutionEngine*, QQmlContextData*, QObject*, QV4::String*, QV4::QObjectWrapper::RevisionMode, QV4::Value const&)
    (engine=engine@entry=0x55555587e240, qmlContext=<optimized out>, object=0x555556b33920, name=name@entry=0x7fffe27ad3d8, revisionMode=revisionMode@entry=QV4::QObjectWrapper::IgnoreRevision, value=...) at /home/david/projects/qt5/qtdeclarative/src/qml/jsruntime/qv4qobjectwrapper.cpp:429
#32 0x00007ffff5d2efcd in QV4::QObjectWrapper::put(QV4::Managed*, QV4::String*, QV4::Value const&) (m=0x7fffe27ad3e0, name=0x7fffe27ad3d8, value=...)
--Type <RET> for more, q to quit, c to continue without paging--q
 at /usr/Quit
(gdb) 
(gdb) q
A debugging session is active.