Thanks for asking @SimonW
I actually killed all main process via ps, but I forgot to call ps -aux which showed the child processes hanging around. Killing these helped freeing the memory. Thanks!
@smth
Solved my problem, thanks! Do you know if that’s a known bug listed on the Python bugtracker? Otherwise it might be worth adding it. Or maybe as a warning to users, it might be useful to modify the Runtime error message to warn users about that if possible?