Multiprocessing Pool.map_async() does not have an error_callback paramter as described here http://docs.python.org/library/multiprocessing.html#multiprocessing.pool.multiprocessing.Pool.map_async I assume this is an old configuration that no longer works... I tried to call that parameter by name and I got a Type Error, plus the actual documentation does not mention it at all (and it is missing from similar functions). Recommend it be removed from the documentation, or else better described and implemented.
Python 3.x seems to have the error_callback parameter on all *_async operations. However, 2.7 lacks it. I think adding the actual error_callback would be deemed as a new feature, so the right thing would just be removing the documentation. I'll whip up a patch to remove this from the documentation
