kwin_x11 (version 5.4.2 in openSUSE Tumbleweed) crashes on session start (every time). After disabling drkonqui, kwin is restarted successfully and works fine after that.

I was able to get a core dump but it's a bit large (over 2 GB, xz-compressed 2.7 MB) so I'm not going to attach it for now.

Stack trace looks like this:

raise
KCrash::defaultCrashHandler(int)
<signal handler called>
as<QV4::RegExpObject>
toVariant
QV4::ExecutionEngine::toVariant
QQmlPropertyPrivate::writeBinding
QQmlBinding::update
setEnabled
QQmlObjectCreator::finalize
QQmlComponentPrivate::complete
QQmlComponentPrivate::completeCreate
QQmlComponent::create
Aurorae::Decoration::init
KWin::Decoration::DecorationBridge::createDecoration
KWin::Client::createDecoration
KWin::Client::updateDecoration
KWin::Client::manage
KWin::Workspace::createClient
KWin::Workspace::workspaceEvent
QAbstractEventDispatcher::filterNativeEvent(QByteArray
QXcbConnection::handleXcbEvent(xcb_generic_event_t*)
QXcbConnection::processXcbEvents()
QObject::event(QEvent*)
QApplicationPrivate::notify_helper(QObject*,
QApplication::notify(QObject*,
QCoreApplication::notifyInternal(QObject*,
QCoreApplicationPrivate::sendPostedEvents(QObject*,
QEventDispatcherUNIX::processEvents(QFlags<QEventLoop::ProcessEventsFlag>)
??
QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>)
QCoreApplication::exec()
kdemain
__libc_start_main
_start

I'll attach full output of "bt full" in a moment.

It looks like something isn't properly initialized yet and the code can't handle it. Unfortunately this part of Qt5 is not documented very well so I have no idea what the v4engine is supposed to do.

Reproducible: Always