Question

I am trying to compile a simple cython extension from the example page here on my Windows 7 64-bit machine with Python 2.6 64-bit version installed. I installed Cython 0.15.1 for Windows 64-bit version from Gohlke’s page.

Basically, the answer from here and here are not my options because I really do need Python 64-bit version to address larger memory. Also, because I am trying to compile using Microsoft SDK for .NET 4, I cannot use the approach in the latter solution.

I tried the steps here and observed the green window but compilation now throws the cannot find vcvarsall.bat error. Following is the sequence of commands I tried:

C:\>cd "Program Files\Microsoft SDKs\Windows\v7.1\"
C:\Program Files\Microsoft SDKs\Windows\v7.1>set DISTUTILS_USE_SDK=1
C:\Program Files\Microsoft SDKs\Windows\v7.1>setenv /x64 /release

Setting SDK environment relative to C:\Program Files\Microsoft SDKs\Windows\v7.1\.
Targeting Windows 7 x64 Release

C:\Program Files\Microsoft SDKs\Windows\v7.1>e:

E:\>cd cython

E:\cython>python setup.py build_ext --inplace
running build_ext
skipping 'fib.c' Cython extension (up-to-date)
building 'fib' extension
error: Unable to find vcvarsall.bat

Any suggestions on how I solve this?

Answer 1

Here is an excerpt from one of my batch files:

rem Configure the environment for 64-bit builds.
rem Use "vcvars32.bat" for a 32-bit build.
"C:\Program Files (x86)\Microsoft Visual Studio 9.0\VC\bin\vcvars64.bat"
rem Convince setup.py to use the SDK tools.
set MSSdk=1
set DISTUTILS_USE_SDK=1 

The 7.1 SDK uses what is effectively VS2010 but Python 2.6 is compiled with VS2008. If you can use the 7.0 SDK (I think it is also known as the .NET 3.5 SDK), you will have access to VS2008’s compiler. It is risky to mix different compilers and runtimes libraries.