Apparently, If Sound notication are enabled, KMessageDialog::questionYesNo freezes when it is shown (not drawn, no buttons) and no sound.

I saw that with KDevelop latest git version (for kf5)

Here is a calltrace (not full though, I need to recompile some packages if needed):

#0  0x00007ffff122ddb9 in syscall () from /lib64/libc.so.6
#1  0x00007fffe7be586f in g_cond_wait () from /usr/lib64/libglib-2.0.so.0
#2  0x00007fffe7bc8b0b in g_once_init_enter () from /usr/lib64/libglib-2.0.so.0
#3  0x00007fffd11f7e18 in gst_object_get_type () from /usr/lib64/libgstreamer-0.10.so.0
#4  0x00007fffd123d261 in gst_registry_get_type () from /usr/lib64/libgstreamer-0.10.so.0
#5  0x00007fffd123d4d5 in gst_registry_get_default () from /usr/lib64/libgstreamer-0.10.so.0
#6  0x00007fffd151701f in ?? () from /usr/lib64/qt5/plugins/phonon4qt5_backend/phonon_gstreamer.so
#7  0x00007fffd150b3cd in ?? () from /usr/lib64/qt5/plugins/phonon4qt5_backend/phonon_gstreamer.so
#8  0x00007fffd150b7f8 in qt_plugin_instance () from /usr/lib64/qt5/plugins/phonon4qt5_backend/phonon_gstreamer.so
#9  0x00007ffff1f4494f in QPluginLoader::instance() () from /usr/lib64/libQt5Core.so.5
#10 0x00007fffe7700368 in ?? () from /usr/lib64/libphonon4qt5.so.4
#11 0x00007fffe7702759 in ?? () from /usr/lib64/libphonon4qt5.so.4
#12 0x00007fffe7702f11 in ?? () from /usr/lib64/libphonon4qt5.so.4
#13 0x00007fffe770378d in Phonon::Factory::backend(bool) () from /usr/lib64/libphonon4qt5.so.4
#14 0x00007fffe7703da3 in ?? () from /usr/lib64/libphonon4qt5.so.4
#15 0x00007fffe76f8d84 in ?? () from /usr/lib64/libphonon4qt5.so.4
#16 0x00007fffe76f642e in ?? () from /usr/lib64/libphonon4qt5.so.4
#17 0x00007fffee5b5282 in NotifyByAudio::notify(KNotification*, KNotifyConfig*) () from /usr/lib64/libKF5Notifications.so.5
#18 0x00007fffee59a041 in KNotificationManager::notify(KNotification*) () from /usr/lib64/libKF5Notifications.so.5
#19 0x00007fffee597918 in KNotification::sendEvent() () from /usr/lib64/libKF5Notifications.so.5
#20 0x00007ffff1f7f08a in QObject::event(QEvent*) () from /usr/lib64/libQt5Core.so.5
#21 0x00007ffff290469c in QApplicationPrivate::notify_helper(QObject*, QEvent*) () from /usr/lib64/libQt5Widgets.so.5
#22 0x00007ffff2909b10 in QApplication::notify(QObject*, QEvent*) () from /usr/lib64/libQt5Widgets.so.5
#23 0x00007ffff1f55d8d in QCoreApplication::notifyInternal(QObject*, QEvent*) () from /usr/lib64/libQt5Core.so.5
#24 0x00007ffff1f58b63 in QCoreApplicationPrivate::sendPostedEvents(QObject*, int, QThreadData*) () from /usr/lib64/libQt5Core.so.5
#25 0x00007ffff1fa3713 in postEventSourceDispatch(_GSource*, int (*)(void*), void*) () from /usr/lib64/libQt5Core.so.5
#26 0x00007fffe7ba37d4 in g_main_context_dispatch () from /usr/lib64/libglib-2.0.so.0
#27 0x00007fffe7ba3a28 in ?? () from /usr/lib64/libglib-2.0.so.0
#28 0x00007fffe7ba3acc in g_main_context_iteration () from /usr/lib64/libglib-2.0.so.0
#29 0x00007ffff1fa3787 in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib64/libQt5Core.so.5
#30 0x00007ffff1f549aa in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib64/libQt5Core.so.5
#31 0x00007ffff2aec015 in QDialog::exec() () from /usr/lib64/libQt5Widgets.so.5
#32 0x00007ffff3d0b3ec in KMessageBox::createKMessageBox(QDialog*, QDialogButtonBox*, QIcon const&, QString const&, QStringList const&, QString const&, bool*, QFlags<KMessageBox::Option>, QString const&, QMessageBox::Icon) () from /usr/lib64/libKF5WidgetsAddons.so.5
#33 0x00007ffff3d0b686 in KMessageBox::createKMessageBox(QDialog*, QDialogButtonBox*, QMessageBox::Icon, QString const&, QStringList const&, QString const&, bool*, QFlags<KMessageBox::Option>, QString const&) ()
   from /usr/lib64/libKF5WidgetsAddons.so.5
#34 0x00007ffff3d0bb52 in KMessageBox::questionYesNoListInternal(QDialog*, QString const&, QStringList const&, QString const&, KGuiItem const&, KGuiItem const&, QString const&, QFlags<KMessageBox::Option>) ()
   from /usr/lib64/libKF5WidgetsAddons.so.5
#35 0x00007ffff3d0bebc in KMessageBox::questionYesNo(QWidget*, QString const&, QString const&, KGuiItem const&, KGuiItem const&, QString const&, QFlags<KMessageBox::Option>) ()
   from /usr/lib64/libKF5WidgetsAddons.so.5
#36 0x00007ffff664c0bd in KDevelop::askUser(QString const&, QString const&, QString const&, QString const&, bool) () from /usr/local/lib64/libKDevPlatformUtil.so.10
#37 0x00007fffedc46e1b in (anonymous namespace)::shouldClear(QString const&) () from /usr/local/lib64/libKDevPlatformSerialization.so.10
#38 0x00007fffedc4783a in KDevelop::ItemRepositoryRegistryPrivate::open(QString const&) () from /usr/local/lib64/libKDevPlatformSerialization.so.10
#39 0x00007fffedc4708e in KDevelop::ItemRepositoryRegistry::ItemRepositoryRegistry(QSharedPointer<KDevelop::ISessionLock> const&) () from /usr/local/lib64/libKDevPlatformSerialization.so.10
#40 0x00007fffedc470ee in KDevelop::ItemRepositoryRegistry::initialize(QSharedPointer<KDevelop::ISessionLock> const&) () from /usr/local/lib64/libKDevPlatformSerialization.so.10
#41 0x00007fffef285693 in KDevelop::DUChain::initialize() () from /usr/local/lib64/libKDevPlatformLanguage.so.10
#42 0x00007ffff7a515b4 in KDevelop::CorePrivate::initialize(KDevelop::Core::Setup, QString) () from /usr/local/lib64/libKDevPlatformShell.so.10
#43 0x00007ffff7a52074 in KDevelop::Core::initialize(QObject*, KDevelop::Core::Setup, QString const&) () from /usr/local/lib64/libKDevPlatformShell.so.10
#44 0x0000000000418943 in main ()

Reproducible: Always

Steps to Reproduce:
1. Have kdevelop crash (kill -9 kdevelop)
2. rerun kdevelop and it tries to show a message related to the previous crash (the message box is frozen)
3.

Actual Results:  
the message box is frozen

Expected Results:  
should not be frozen