Cython crashes when trying to build extension from __init__.py

I’ve noticed this on some occasions. When Cython tries to build an extension module with distutils, it crashes and spits out an error like this. Here is me trying to compile a test __init__ file from the command line.

C:\Users\You>cythonize -i -3 __init__.py
running build_ext
building 'You.__init__' extension
creating C:\Users\tmpo_kxxv5_\Release
creating C:\Users\tmpo_kxxv5_\Release\Users
creating C:\Users\tmpo_kxxv5_\Release\Users\You
C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\BIN\x86_amd64\cl.exe /c /
nologo /Ox /W3 /GL /DNDEBUG /MD -Ic:\python37\include -Ic:\python37\include "-IC
:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\INCLUDE" "-IC:\Program Fil
es (x86)\Microsoft Visual Studio 14.0\VC\ATLMFC\INCLUDE" "-IC:\Program Files (x8
6)\Windows Kits\10\include\10.0.17763.0\ucrt" "-IC:\Program Files (x86)\Windows
Kits\NETFXSDK\4.6.1\include\um" "-IC:\Program Files (x86)\Windows Kits\10\includ
e\10.0.17763.0\shared" "-IC:\Program Files (x86)\Windows Kits\10\include\10.0.17
763.0\um" "-IC:\Program Files (x86)\Windows Kits\10\include\10.0.17763.0\winrt"
/TcC:\Users\You\__init__.c /FoC:\Users\tmpo_kxxv5_\Release\Users\You\__init__.ob
j
__init__.c
C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\BIN\x86_amd64\link.exe /n
ologo /INCREMENTAL:NO /LTCG /DLL /MANIFEST:EMBED,ID=2 /MANIFESTUAC:NO /LIBPATH:c
:\python37\libs /LIBPATH:c:\python37\PCbuild\amd64 "/LIBPATH:C:\Program Files (x
86)\Microsoft Visual Studio 14.0\VC\LIB\amd64" "/LIBPATH:C:\Program Files (x86)\
Microsoft Visual Studio 14.0\VC\ATLMFC\LIB\amd64" "/LIBPATH:C:\Program Files (x8
6)\Windows Kits\10\lib\10.0.17763.0\ucrt\x64" "/LIBPATH:C:\Program Files (x86)\W
indows Kits\NETFXSDK\4.6.1\lib\um\x64" "/LIBPATH:C:\Program Files (x86)\Windows
Kits\10\lib\10.0.17763.0\um\x64" /EXPORT:PyInit___init__ C:\Users\tmpo_kxxv5_\Re
lease\Users\You\__init__.obj /OUT:C:\Users\You\__init__.cp37-win_amd64.pyd /IMPL
IB:C:\Users\tmpo_kxxv5_\Release\Users\You\__init__.cp37-win_amd64.lib

LINK : error LNK2001: unresolved external symbol PyInit___init__
C:\Users\tmpo_kxxv5_\Release\Users\You\__init__.cp37-win_amd64.lib : fatal error
 LNK1120: 1 unresolved externals

error: command 'C:\\Program Files (x86)\\Microsoft Visual Studio 14.0\\VC\\BIN\\
x86_amd64\\link.exe' failed with exit status 1120

Not only that, but it creates pyd fieles when then crash the program if something tries to import them because there empty. I believe the error is caused by PyInit___init__, which probably is aukward enough to cause the compiler to throw an error. The contents of the init file is: ‘’‘testing file’‘’ pass

[Keithcat1]

Must’ve been from pip. I got my current cython version from the command: “pip install cython==3.0a5” Anyway, it works now.

[Keithcat1]

Thanks! I guess I need to download Cython from Github and install that if I want to compipe init