Set default compiler by platform in setup.cfg?

[colemathis]

I'm developing a package with a fairly complex install process that requires building external libraries in C++ and CGo. Surprisingly, everything is working well on Ubuntu and Windows. The only restriction is that I need to use MinGW as the compiler on Windows (this is a CGo requirement).

I can make this work by setting these flags in setup.cfg

[build]
compiler=mingw32

[build_ext]
compiler=mingw32

The problem is that if I have these flags I cannot build on Ubuntu because it looks for MinGW, doesn't find it and fails.

Is there a way to tell setup() to only use that compiler if the platform is Windows? I'd prefer to not use command line arguments and just build via pip install ... on all platforms.