Ninja build on Windows

[inakleinbottle]

Are there any plans to allow for Ninja builds on Windows? MSBuild is dreadfully slow - A simple package I build takes ~ 100 seconds to build a single wheel on Windows, whilst MacOS finishes all 6 of its builds in 125 seconds.

MSVC does have support for Ninja, and if I remember correctly SciKit-Build did once support Ninja builds on Windows, which as much faster.

What are the obstacles for supporting Ninja with MSVC builds? Can they be added in a vendored scikit-build-core for my larger complex builds?

[tikuma-lsuhsc]

I cannot speak of the scikit-build-core's native support, but you can always add CMAKE_GENERATOR system environment variable and set it to Ninja and CMake will use it by default. This works fine with scikit-build-core.

https://cmake.org/cmake/help/latest/variable/CMAKE_GENERATOR.html

[henryiii]

Are you sure it’s the build system is the problem and not the compiler? MSVC is very slow. But yes, you can set -GNinja in your CMake args or the envvar above and scikit-build-core will adapt.

[inakleinbottle]

Actually the problem that I have is that I can set the generator to Ninja, but it doesn't find the correct compiler in GitHub actions. Honestly I'd like to use anything other than MSVC because of its many shortcomings, but I guess it is the only way to ensure compatibility with Windows users. I know the Numpy devs are considering using clang-cl instead, but AFAIK they haven't moved over yet for much the same reason.

[henryiii]

You need to setup msvc to get ninja to find it. Something like https://github.com/ilammy/msvc-dev-cmd should work.

[inakleinbottle]

OK that's great, I'll take a look!