We observe an issue roughly 10% of the time where an OpenHTF test completes but then hangs and never returns to the parent thread. It seems like one of the threads in OpenHTF is hanging at exit, but we haven't been able to figure out what thread it is. Have you folks seen this issue before? Any idea what steps we should take to try to figure out why this is happening?
If you hit Ctrl-C to kill it once it is hung, this is the output:

We're not sure if it's related, but we've also seen issues with tests starting in an already stopped state. It also seems to be some sort of threading race condition. We were only able to resolve it by adding a 1 second sleep into init.py after self._executor.start(): ShaperTools@ccdc014
cc: @shaperilio