multiprocessing.Pool 捕获error

调用 pool.apply_async 后没有报错直接退出,导致我一直以为是 join 后主进程没有阻塞，直接结束导致子进程直接退出。原来是子进程的执行时有error,但是没有捕获到

import multiprocessing as mp

class A:
    def __init__(self,re):
        self.re = re

def do_stuff(num):
    result = 5/(2 - num)  #Line 8
    return A(result) 

def success_handler(result:A):
    print("success",result.re)

def error_handler(e):
    print(e.__cause__)

if __name__ == '__main__':
    with mp.Pool(2) as my_pool:
        results =  [
            my_pool.apply_async(
                do_stuff, 
                args=(i,),
                callback=success_handler, 
                error_callback=error_handler
            ) 
            for i in range(3)
        ]

        try:
            for result_obj in results:
                print("result is: {}".format(result_obj.get()))
        except ZeroDivisionError as e:
            print("Oh, boy.  This is the second time I've seen this error.")