When running tests I encounter the following error for the test:

test_sock_sendfile_not_regular_file (test.test_asyncio.test_proactor_events.ProactorEventLoopUnixSockSendfileTests)

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Microsoft Visual C++ Runtime Library
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Debug Assertion Failed!

Program: ...\EP2018\cpython\PCbuild\win32\python_d.exe
File: minkernel\crts\ucrt\src\appcrt\lowio\osfinfo.cpp
Line: 257

Expression: fh >= 0 && (unsigned)fh < (unsigned)_nhandle


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However, when ignoring the MSCR error, the tests succeed without failing.

In addition the following failed (but not consistently):

======================================================================
FAIL: test_sendfile_close_peer_in_the_middle_of_receiving (test.test_asyncio.test_events.ProactorEventLoopTests)
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Traceback (most recent call last):
  File "C:\Users\woellert\Desktop\EP2018\cpython\lib\test\test_asyncio\test_events.py", line 2510, in test_sendfile_close_peer_in_the_middle_of_receiving
    self.file.tell())
AssertionError: False is not true : 131072

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Specs: Windows 7 SP1 64bit, 

Process:
- Cloned master from github
- Installed Visual Studio 2017 Community
- Compiled with `PCbuild\build.bat -e -d` (also used 64bit via -p x64)
- Ran tests with `python.bat -m test.test_asyncio -v`