Often, when running a QML based app, i have a deadlock as followed:

frame #0: 0x00007fff99af0132 libsystem_kernel.dylib`__psynch_cvwait + 10
frame #1: 0x00007fff9bc55ea0 libsystem_pthread.dylib`_pthread_cond_wait + 693
frame #2: 0x00000001016aab51 libQt5Core_debug.5.3.2.dylib`QWaitConditionPrivate::wait(unsigned long) + 81
frame #3: 0x00000001016aa90f libQt5Core_debug.5.3.2.dylib`QWaitCondition::wait(QMutex*, unsigned long) + 207

• frame #4: 0x0000000103c131a1 libQt5Quick_debug.5.dylib`QSGThreadedRenderLoop::polishAndSync(QSGThreadedRenderLoop::Window*) + 513
  frame #5: 0x0000000103c13771 libQt5Quick_debug.5.dylib`QSGThreadedRenderLoop::event(QEvent*) + 289
  frame #6: 0x00000001019e6458 libQt5Core_debug.5.3.2.dylib`QCoreApplicationPrivate::notify_helper(QObject*, QEvent*) + 136
  frame #7: 0x00000001019e63aa libQt5Core_debug.5.3.2.dylib`QCoreApplication::notify(QObject*, QEvent*) + 186
  frame #8: 0x000000010228ecc8 libQt5Gui_debug.5.dylib`QGuiApplication::notify(QObject*, QEvent*) + 264
  frame #9: 0x00000001019e6269 libQt5Core_debug.5.3.2.dylib`QCoreApplication::notifyInternal(QObject*, QEvent*) + 201
  frame #10: 0x00000001019eb2c4 libQt5Core_debug.5.3.2.dylib`QCoreApplication::sendEvent(QObject*, QEvent*) + 84
  frame #11: 0x0000000101a838bc libQt5Core_debug.5.3.2.dylib`QTimerInfoList::activateTimers() + 732
  frame #12: 0x000000010b72e754 libqcocoa_debug.dylib`QCocoaEventDispatcherPrivate::activateTimersSourceCallback(void*) + 36
  frame #13: 0x00007fff90ae5661 CoreFoundation`_CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION_ + 17
  frame #14: 0x00007fff90ad77ed CoreFoundation`__CFRunLoopDoSources0 + 269
  frame #15: 0x00007fff90ad6e1f CoreFoundation`__CFRunLoopRun + 927
  frame #16: 0x00007fff90ad6838 CoreFoundation`CFRunLoopRunSpecific + 296
  frame #17: 0x00007fff97c3143f HIToolbox`RunCurrentEventLoopInMode + 235
  frame #18: 0x00007fff97c311ba HIToolbox`ReceiveNextEventCommon + 431
  frame #19: 0x00007fff97c30ffb HIToolbox`_BlockUntilNextEventMatchingListInModeWithFilter + 71
  frame #20: 0x00007fff94683821 AppKit`_DPSNextEvent + 964
  frame #21: 0x00007fff94682fd0 AppKit`-[NSApplication nextEventMatchingMask:untilDate:inMode:dequeue:] + 194
  frame #22: 0x00007fff94676f73 AppKit`-[NSApplication run] + 594
  frame #23: 0x000000010b72f4a3 libqcocoa_debug.dylib`QCocoaEventDispatcher::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) + 1155
  frame #24: 0x00000001019e1a3a libQt5Core_debug.5.3.2.dylib`QEventLoop::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) + 122
  frame #25: 0x00000001019e1c6e libQt5Core_debug.5.3.2.dylib`QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) + 542
  frame #26: 0x00000001019e6a29 libQt5Core_debug.5.3.2.dylib`QCoreApplication::exec() + 393
  frame #27: 0x000000010228ebb6 libQt5Gui_debug.5.dylib`QGuiApplication::exec() + 22