Summary

The 1.22 series are using the latest VS2019 toolchain (version 142). This makes the built objects and static libraries incompatible with software built with older toolchains. Would you accept a PR to use the older VS2017 version 141 toolchain instead?

Detail

The Numpy 1.22 series wheels are breaking the Scipy MinGW-w64 builds.

I believe this is because y'all have updated from the previous VS2017 toolchain (version 141) to the latest VS2019 toolchain (version 142).

As MS point out, using version 142 to build the static libraries means that anyone linking against those libraries must also be using (at least) this toolchain.

This means that projects like Scipy can't link to Numpy without also updating to version 142.

In fact, for Scipy, it also, and presumably for similar reasons, breaks our ability to link using MinGW-w64:

matthew-brett/dll_investigation#1

I believe, for these reasons, conda-forge has standardized to version 141 for their builds.

Would y'all consider following conda-forge, and using the 141 toolchain for builds, so that more of us can safely
link to Numpy - particularly - npymath?

@isuruf tells me that this just requires the following lines for a Visual Studio 2019 image:

call "C:\Program Files (x86)\Microsoft Visual Studio\2019\Enterprise\VC\Auxiliary\Build\vcvars64.bat" -vcvars_ver=14.16
set DISTUTILS_USE_SDK=1

@isuruf points out that

Last part is to make sure that distutils doesn't try to override that if you are using distutils.

@rgommers @carlkl