Qt 5.13, I set up the scan for devices based on the example in the QT documentation. I can start and successfully scan for devices on my MAC. The problem is that once any single device is discovered, the entire application will crash with a segmentation fault. Even after receiving the finished signal, the stop() to the agent crashes the system. When the application starts I do get this warning: qt.bluetooth.osx: IOBluetooth works only on the main thread or a thread with a running CFRunLoop. My thread is handling events fine, but I don't know if the above warning is specifically issues because there is no CFrunloop or it is a general warning. How do I know if my thread has a CFRunloop? Is there something else I should be looking at?