Remote executed application does not stop: no termination signal received

What I try to do with Qt Creator and qbs is starting generated Python scripts remotely. Starting the scripts works perfectly, but stopping just results in a timeout. I have tried to register signal handlers to all possible UNIX signals but none seems to be triggered by Qt Creator. Can you please give some insights what exactly Qt Creator is doing when the stop button is pressed for Remote Linux applications? Here is the Python script executed remotely: https://github.com/strahlex/MachinekitLauncher