Assert error in ntoskrnl/io/iomgr/iomdl.c when run test_multiprocessing_spawn.py in Python 3.4.0

*** Assertion failed: Length != 0

***   Source File: /srv/buildbot/Build_GCCLin_x86/build/ntoskrnl/io/iomgr/iomdl.c, line 33

Break repeatedly, break Once, Ignore, terminate Process or terminate Thread (boipt)? 

kdb:> b

Execute '.cxr F6CB8760' to dump context

[7h

Entered debugger on embedded INT3 at 0x0008:0x8093c18e.

kdb:> bt

Eip:

<NTOSKRNL.EXE:13c18f (:0 (DbgBreakPoint))>

Frames:

<NTOSKRNL.EXE:680b5 (ntoskrnl/io/iomgr/iomdl.c:33 (IoAllocateMdl))>

<afd.sys:4b1e (drivers/network/afd/afd/lock.c:106 (LockRequest))>

<afd.sys:9e4c (drivers/network/afd/afd/read.c:451 (AfdConnectedSocketReadData))>

<afd.sys:710b (drivers/network/afd/afd/main.c:871 (AfdDispatch))>

<NTOSKRNL.EXE:6a60b (ntoskrnl/io/iomgr/irp.c:1223 (IofCallDriver))>

<NTOSKRNL.EXE:620f1 (ntoskrnl/io/iomgr/iofunc.c:139 (IopPerformSynchronousRequest))>

<NTOSKRNL.EXE:65c26 (ntoskrnl/io/iomgr/iofunc.c:2750 (NtReadFile))>

<NTOSKRNL.EXE:1212f4 (ntoskrnl/include/internal/i386/ke.h:706 (KiSystemServiceHandler))>

<NTOSKRNL.EXE:3da9 (:0 (KiFastCallEntry))>

<ntdll.dll:c81d>

<python34.dll:8131d>

C:\Python34\python.exe -m test -S test_multiprocessing_spawn