"error: Unable to find vcvarsall.bat" when compiling Cython code

Question

As suggested here, I have succesfully installed Microsoft Visual C++ Compiler for Python 2.7 to compile some Cython code, but:

from distutils.core import setup
from Cython.Build import cythonize
setup(ext_modules = cythonize("module1.pyx"))

still produces:

error: Unable to find vcvarsall.bat

How to compile Cython code with Python 2.7 (for example on Windows 7 x64)?

Note: I already carefully read the question error: Unable to find vcvarsall.bat but the main answers (including modifying msvc9compiler.py) didn't solve it.

Nympholepsy

@NewEnglandcottontail: doesn't python -m pip install --upgrade setuptools solve your question? also what's the VStudio version you have installed? – Equilibrium

Answer 1

I spent hours on this, and the information was not easily findable in error: Unable to find vcvarsall.bat, that's why I post it here with the "answer your own question" feature:

• Step 1: Install Microsoft Visual C++ Compiler for Python 2.7

• Remark: You don't need to modify msvc9compiler.py as often suggested in many forum posts

• Step 2: Just add import setuptools that will help Python and "Microsoft Visual C++ Compiler for Python 2.7" work together.

  import setuptools  # important
  from distutils.core import setup
  from Cython.Build import cythonize
  setup(ext_modules=cythonize("module1.pyx", build_dir="build"),
                                             script_args=['build'], 
                                             options={'build':{'build_lib':'.'}})
  

  Note: the script_args parameter allows to run this setup.py with just python setup.py (i.e. CTRL+B in your favorite editor like Sublime Text) instead of having to pass command-line arguments like this: python setup.py build.

It works!

Nympholepsy

just adding "import setuptools" made the error disappear – Erode

The link in step 1 is not available anymore :( – Chigetai

Answer 2

Python >= 3.5

I wanted to comment on @Basj (https://mcmap.net/q/654060/-quot-error-unable-to-find-vcvarsall-bat-quot-when-compiling-cython-code) answer but I couldn't so I apologize. I just want to add to @Basj answer for people using Python >= 3.5, instead of Microsoft Visual C++ Compiler for Python 2.7, you can install just the C++ in this installer Build Tool for Visual Studio 2019 or you can simply install that with Chocolatey.

Areola

The link for 'Build Tool for Visual Studio 2019' leads me to download the whole Visual Studio. Is this intended? – Oxide

@Idonknow, yes, the download link for Build Tool for Visual Studio is the whole Visual Studio but during the installation process, you can choose which package to install. I would suggest Chocolatey as it is much easier! – Areola

what if your installation is within a virtual enviroment? – Crwth

Good question, I don't think i have the answer for that. I guess you still have to install the C++ compiler on the whole system?! – Areola

the installer of visual studio, asks for 6.46GB to install the C++ build tools !!! – Modern

@Yehdhih ANNA that is why I suggest the chocolatey as in my answer above as well as my reply to Idonknow's question above! – Areola

Answer 3

The solution that fixed it for me. Use Git Bash and use the following:

INCLUDE="C:/Program Files (x86)/Windows Kits/10/Include/10.0.22621.0/ucrt/;C:/Program Files (x86)/Windows Kits/10/Include/10.0.22621.0/shared/" \
> LIB="C:/Program Files (x86)/Windows Kits/10/Lib/10.0.22621.0/ucrt/x64;C:/Program Files (x86)/Windows Kits/10/Lib/10.0.22621.0/um/x64" \
> PATH=$PATH:/c/Program\ Files\ \(x86\)/Windows\ Kits/10/bin/10.0.22621.0/x64 \
> python -m pip install <package>

Then run python setup.py build_ext --inplace

Git Bash will detect visual Studio Cmd, Anaconda do not. I am running Microsoft Visual Studio 2022, Microsoft Visual Studio Tools and Microsoft Visual 2017 v 14.00

Theoretical solutions I tried that didn't help me but others said it work below:

The same reason this issue is present these days is because Microsoft made it. Likely a pathing issue and issue is reappearing which is Microsoft specialty since 2018.

https://github.com/pypa/setuptools/issues/3329

This might fix for you but again this is Microsoft:

import setuptools  # as requested
import distutils._msvccompiler

You can also change/check regedit:

[HKEY_LOCAL_MACHINE\SOFTWARE\WOW6432Node\Microsoft\VisualStudio\14.2\Setup\VC]
"ProductDir"="C:\\Program Files (x86)\\Microsoft Visual Studio\\2019\\BuildTools\\VC\\Auxiliary\\Build"

[HKEY_LOCAL_MACHINE\SOFTWARE\WOW6432Node\Microsoft\VisualStudio\14.0\Setup\VC]
"ProductDir"="C:\\Program Files (x86)\\Microsoft Visual Studio\\2019\\BuildTools\\VC\\Auxiliary\\Build"

Another option is to check the correct environment variables as well as delete any and all visual Studio stuff you do not need/use.

environment variable path and delete old ones and restart pc afterwards:

    C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\bin\amd64_arm
    C:\Users\AAAAA\AppData\Local\Programs\Microsoft VS Code\bin
    C:\Program Files (x86)\Windows Kits\10\bin\10.0.22621.0\x64

Use Anaconda and use the following:

    SET DISTUTILS_USE_SDK=1 & "C:\Program Files (x86)\Microsoft Visual Studio\2022\BuildTools\VC\Auxiliary\Build\vcvarsall.bat" x64

https://learn.microsoft.com/en-us/answers/questions/419525/microsoft-visual-c-140-or-greater-is-required.html

Ouphe

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