import threading
import os
import sys

class ForkThread(threading.Thread):
    def run(self):
        print("thread: before fork", list(threading.enumerate()))
        pid = os.fork()
        if pid:
            # parent: wait for the child
            os.waitpid(pid, 0)
            return

        # child
        print("thread: after fork", list(threading.enumerate()))
        print("thread: after fork: raise")
        raise Exception("what happens here?")
        #sys.exit(1)

thread = ForkThread()
print("main thread: spawn fork thread")
thread.start()
thread.join()
print("main thread: done")