Specifically:

>>> import multiprocessing
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/Users/jesse/open_source/subversion/python-
trunk/Lib/multiprocessing/__init__.py", line 63, in <module>
import _multiprocessing
AttributeError: 'module' object has no attribute 'BufferTooShort'

This occurs due to the fact that __init__.py imports _multiprocessing 
prior to the definition of the exceptions. This should be moved to the 
ccode. From Georg:

"The test suite passes (at least for some buildbots) because it imports
_multiprocessing first, which then in its init function imports 
multiprocessing
to get the BufferTooShort exception.

Since BufferTooShort and other exceptions inheriting from ProcessError 
are
simple derived exceptions, why aren't they created in the C module in 
the
first place?"