I'm seeing this on Linux. For whatever reason, the ctypes module on this server (Debian lenny, Python2.5) does not provide WINFUNCTYPE.

Traceback (most recent call last): File "/root/cogen/cogen/core/proactors/init.py", line 79, in has_ctypes_iocp import ctypes_iocp_impl File "/root/cogen/cogen/core/proactors/ctypes_iocp_impl/init.py", line 4, in <module> from api_wrappers import _get_osfhandle, CreateIoCompletionPort, CloseHandle, \ File "/root/cogen/cogen/core/proactors/ctypes_iocp_impl/api_wrappers.py", line 1, in <module> from ctypes import WINFUNCTYPE, GetLastError, \ ImportError: cannot import name WINFUNCTYPE

I see now that this traceback is just a dump of a handled error. This was a bit of a red herring. Unless the traceback is helping you track down bugs, I'd drop it. In particular, on Linux, it shouldn't complain at all.

Ah right, I forgot that while developing the ctypes iocp proactor. I've removed that debug traceback.