Compiler problems with pip during numpy install under Windows 8.1, 7 Enterprise and 7 Home Editions

Question

I am unable to install numpy via pip install numpy on my computer running Python 3.4 due to various errors I receive linked to compilation issues (This is only the case on a 64-bit installation of Python).

This is a problem that has been reported extensively and I had a related question about unable to find vcvarsall.bat. I have tested this on three different clean machines running Windows 8.1, 7 Enterprise and 7 Home Editions and it always comes up.

Installing Visual Studio 2010 Express C++ gets rid of the first error in the link - i.e. Unable to find vcvarsall.bat but throws out a next exception ending with a ValueError as here:

  File "C:\Python34\lib\distutils\msvc9compiler.py", line 371, in initialize

    vc_env = query_vcvarsall(VERSION, plat_spec)

  File "C:\Python34\lib\distutils\msvc9compiler.py", line 287, in query_vcvarsall

    raise ValueError(str(list(result.keys())))

ValueError: ['path']

I have then followed this advice and patched the file as linked in the discussion forum which resulted in a KEY_BASE error.

  File "C:\Users\Matej\AppData\Local\Temp\pip_build_Matej\numpy\numpy\distutils\command\config.py", line 18, in <module>

    from numpy.distutils.mingw32ccompiler import generate_manifest

  File "C:\Users\Matej\AppData\Local\Temp\pip_build_Matej\numpy\numpy\distutils\mingw32ccompiler.py", line 36, in <module>

    from distutils.msvccompiler import get_build_version as get_build_msvc_version

  File "C:\Python34\lib\distutils\msvccompiler.py", line 638, in <module>

    from distutils.msvc9compiler import MSVCCompiler

  File "C:\Python34\lib\distutils\msvc9compiler.py", line 71, in <module>

    r"v%sA"

  File "C:\Python34\lib\distutils\msvc9compiler.py", line 67, in <listcomp>

    WINSDK_PATH_KEYS = [KEY_BASE + "Microsoft SDKs\\Windows\\" + rest for rest in (

NameError: name 'KEY_BASE' is not defined

Following the advice in the same link, I have added the following definition of KEY_BASE before the variable gets called in msvc9compiler.py:

KEY_BASE = r"Software\Microsoft\\"

Which results in the final error I was not able to troubleshoot:

  File "C:\Users\Matej\AppData\Local\Temp\pip_build_Matej\numpy\numpy\distutils\command\build_src.py", line 164, in build_sources

    self.build_library_sources(*libname_info)

  File "C:\Users\Matej\AppData\Local\Temp\pip_build_Matej\numpy\numpy\distutils\command\build_src.py", line 299, in build_library_sources

    sources = self.generate_sources(sources, (lib_name, build_info))

  File "C:\Users\Matej\AppData\Local\Temp\pip_build_Matej\numpy\numpy\distutils\command\build_src.py", line 386, in generate_sources

    source = func(extension, build_dir)

  File "numpy\core\setup.py", line 682, in get_mathlib_info

    raise RuntimeError("Broken toolchain: cannot link a simple C program")

RuntimeError: Broken toolchain: cannot link a simple C program

I have tried the following but none of it resolved the Broken toolchain error:

• This link that includes a further patch to msvc9compiler.py
• This link by Peter Cock (This helps on the 32-bit install of Python3.4)
• Tried installing using easy_install as some users suggested it might work that way

NOTE 1: I am aware of the workaround using the compiled binaries on this website I am specifically looking for solution using distutils if there is one. NOTE 2: The error logs are obviously larger and I cut them for readability.

Answer 1

I was able to reproduce all these errors in Windows 7 Professional (64 bit).

Your final issue (Broken toolchain) is caused by more manifest related issues. I was able to work around this by changing the following line (in msvc9compiler.py):

mfinfo = self.manifest_get_embed_info(target_desc, ld_args)

to

mfinfo = None

thus bypassing the if statement which immediately follows. After this change numpy successfully compiled for me.

Answer 2

Although the accepted answer is working, it's an unnecessary monkey-patch to a battle-tested library.

To fix the issue at it's core: Simply add (x86 or x64 - depending on your target) Microsoft Manifest Tool (mt.exe) to your path and install numpy through pip.

Since Visual Studio 2017, mt.exe has moved to the Windows SDK 7.1/8.1/10, which needs to be installed.

My mt.exe (x86) is located in: C:\Program Files (x86)\Windows Kits\10\bin\10.0.18362.0\x86 so that's what I have added to the path, do that ether through Control Panel > System > Advanced system settings > Environment Variables or by using the pathman command in the console (cmd.exe).

Hope it helps, happy compiling!