With this code: #!/usr/bin/env python
from processing import Pool, Process, Manager, Lock import sys def slow_operation(i, q, lk): print "id: ", i # some really slow operation... print "qcquiring lock..." try: lk.acquire(blocking=True) q.put("result") lk.release() except: print sys.exc_info() mgr = Manager() qlk = mgr.Lock() slow_operation_result = mgr.Queue() pool = Pool(10) oid_range = [(i, slow_operation_result, qlk) for i in range(1,200)] async_result = pool.map_async(slow_operation, oid_range) async_result.wait() I get a bunch of these errors: Process PoolWorker-#: Traceback (most recent call last): File "/usr/ lib/python2.5/site-packages/processing/process.py", line 227, in _bootstrap self.run() File "/usr/lib/python2.5/site-packages/ processing/process.py", line 85, in run self._target(*self._args, **self._kwargs) File "/usr/lib/python2.5/site-packages/processing/ pool.py", line 54, in worker for job, i, func, args, kwds in iter(inqueue.get, None): File "/usr/lib/python2.5/site-packages/ processing/queue.py", line 327, in get return recv() File "/usr/lib/ python2.5/site-packages/processing/managers.py", line 869, in RebuildProxy incref=incref, **kwds) File "/usr/lib/python2.5/site- packages/processing/managers.py", line 907, in MakeAutoProxy proxy = ProxyType(token, manager=manager, authkey=authkey, incref=incref) File "/usr/lib/python2.5/site-packages/processing/managers.py", line 718, in __init__ self._incref() File "/usr/lib/python2.5/site-packages/ processing/managers.py", line 763, in _incref assert self._id not in self._idset AssertionError: (AssertionError(), , (, Token(typeid='Queue', address='/tmp/pyc-1705-0-PUnclX', id=25638024), {'exposed': ('empty', 'full', 'get', 'get_nowait', 'join', 'put', 'put_nowait', 'qsize', 'task_done')})) Interpreter version: Python 2.5.2 (what ships with debian stable) Processing lib version: 0.52 Why does this fail? -- http://mail.python.org/mailman/listinfo/python-list