crash when exiting the application

On a fully up-to-date trusty desktop and with calendar-app latest trunk, I can reliably reproduce the following crash by just launching the application and exiting it:

#0 0x00007ffff60dd547 in testAndSetRelaxed<QMutexData*> (newValue=<optimized out>, expectedValue=<optimized out>,
    _q_value=<optimized out>) at ../../include/QtCore/../../src/corelib/arch/qatomic_x86.h:256
#1 testAndSetAcquire<QMutexData*, QMutexData*> (newValue=<optimized out>, expectedValue=<optimized out>,
    _q_value=<optimized out>) at ../../include/QtCore/../../src/corelib/thread/qgenericatomic.h:150
#2 testAndSetAcquire (newValue=<optimized out>, expectedValue=<optimized out>, this=<optimized out>)
    at ../../include/QtCore/../../src/corelib/thread/qbasicatomic.h:231
#3 fastTryLock (this=<optimized out>) at thread/qmutex.h:86
#4 QMutex::lock (this=0xba0) at thread/qmutex.cpp:212
#5 0x00007fffce915842 in QtOrganizer::QOrganizerAbstractRequest::cancel() ()
   from /usr/lib/x86_64-linux-gnu/libQt5Organizer.so.5
#6 0x00007fffcc88dcac in QOrganizerEDSEngine::~QOrganizerEDSEngine() ()
   from /usr/lib/x86_64-linux-gnu/qt5/plugins/organizer/libqtorganizer_eds.so
#7 0x00007fffcc88de29 in QOrganizerEDSEngine::~QOrganizerEDSEngine() ()
   from /usr/lib/x86_64-linux-gnu/qt5/plugins/organizer/libqtorganizer_eds.so
#8 0x00007fffce91ebb2 in QtOrganizer::QOrganizerManager::~QOrganizerManager() ()
   from /usr/lib/x86_64-linux-gnu/libQt5Organizer.so.5
#9 0x00007fffce91ec79 in QtOrganizer::QOrganizerManager::~QOrganizerManager() ()
   from /usr/lib/x86_64-linux-gnu/libQt5Organizer.so.5
#10 0x00007fffcd1e7e78 in ?? () from /usr/lib/x86_64-linux-gnu/qt5/qml/QtOrganizer/libdeclarative_organizer.so
#11 0x00007fffcd1b9046 in ?? () from /usr/lib/x86_64-linux-gnu/qt5/qml/QtOrganizer/libdeclarative_organizer.so
#12 0x00007ffff62859bc in QObjectPrivate::deleteChildren (this=this@entry=0x9527e0) at kernel/qobject.cpp:1764
#13 0x00007ffff628c792 in QObject::~QObject (this=0x951520, __in_chrg=<optimized out>) at kernel/qobject.cpp:857
#14 0x00007ffff7922ca7 in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Quick.so.5
#15 0x00007ffff62859bc in QObjectPrivate::deleteChildren (this=this@entry=0x839ea0) at kernel/qobject.cpp:1764
#16 0x00007ffff628c792 in QObject::~QObject (this=0x7fffffffdc50, __in_chrg=<optimized out>) at kernel/qobject.cpp:857
#17 0x00007ffff74c4f5d in QQmlEngine::~QQmlEngine() () from /usr/lib/x86_64-linux-gnu/libQt5Qml.so.5
#18 0x0000000000403e2f in ?? ()
#19 0x00007ffff56adec5 in __libc_start_main (main=0x4036e0, argc=2, argv=0x7fffffffdde8, init=<optimized out>,
    fini=<optimized out>, rtld_fini=<optimized out>, stack_end=0x7fffffffddd8) at libc-start.c:285
#20 0x0000000000406133 in ?? ()