multiprocessing 的 debug 问题 ？

multiprocessing 的子进程错误完全没有错误提示，要怎样才能 debug 呢 ？

环境是 windows python 2.7

例如下面这段带码

#-*-coding:utf-8-*-
import multiprocessing
from multiprocessing import Pool,Process,Queue
import time
import pdb

def add(i,item,queue):
    item["i"] = i
    queue.put(item)

def store(queue):
    time.sleep(1)
    while True:
        print queue.get()

if __name__ == "__main__":
    item = {}
    manager = multiprocessing.Manager()
    queue = manager.Queue()
    pool = Pool()
    pool.apply_async(store,args = (queue,))
    try:
        for i in range(10):
            pool.apply_async( add, args = (i,item,queue,"这里多了个参数但没任何错误提示"))
            #pool.apply_async( add, args = (i,item,queue)) #这样可以正常运行
    except Exception,e:
        print Exception,":",e
    time.sleep(2)
    pool.terminate()
    pool.join()