atexit and sys.excepthook get ignored when Qt crashes

When a Qt error crashes the program, such as this one: 

https://bugreports.qt.io/browse/PYSIDE-933

Or when calling a Qt function from a python thread, or a myriad of other reasons, the program will improperly exit, often segfaulting. This leads to sys.excepthook and atexit from python not being called and preventing proper freeing of resoures.

Such as, in my case, I have a concurrent.futures.ProcessPoolExecutor to offload CPU intensive tasks without incurring the GIL tax. However, the pool.join() methods do not get called in the event of a Qt related crash, as the responsible functions never get called orphaning the processes forever. This leads to resources being bound until a restart of the system. It also leads to a very common problem that keeps occuring in our Support:

Software crashes on Customer end.

Customer calls support

support tells them to update

Customer downloads and installs update

update fails because software is still open (the zombie processes)

support has to go onto customer computer and kill cpucount many processes, then proceed with installation

The updater software has an option to attempt to close the processes, but they do not respond and the installer software has no option to tell it to just term the processes.