MinGW platform

[ghost]

MinGW is not a POSIX platform. On latest MSYS2, there is no packages for OCaml for the POSIX environment MSYS. Now, there are only packages for OCalm for the MinGW-based environments (e.g: MINGW32, MINGW64, UCRT64,...). The legacy MSYS 1.0 and original MinGW-Org are long gone as there are only MSYS2 and MinGW-w64 now.

The Python packages on MinGW-based environments of MSYS2 will report the platform as: print(os.name) is nt and print(platform.system().lower()) is window. The result is the same as normal standalone Python version.

Please update the build system and the build scripts accordingly. Thank you.

[ghost]

uname -s on MSYS2 will include the Windows version, e.g: uname -s on UCRT64 will print MINGW64_NT-6.3-9600 (I'm using Windows 8.1). To reliably check for MSYS2 platform, you should check for the MSYSTEM environment variable. If MSYSTEM is defined, it's pretty sure that we are running on MSYS2.

[skaller]

I didn't write the build systems "fbuild" and find it more or less impenetrable. I also don't have a Windows box to do any testing (I'm using a Mac). So if you can patch it, feel free (please test the build on your platform though).