> I think this is very common. But it means that people who really want their code to actually compile on Windows frequently have an inferior system with which to do it, because all the real hackers are cross compiling from Linux.
Or Cygwin. Part of the point is the exact same process should result in the same built binaries for cross-compilation from Linux or cross-compilation from Cygwin. Any complaint about Cygwin in terms of size or performance applies equally to MSYS2, and MSYS2's newness and multitude of build/run modes causes more trouble than it's worth in many cases. > or provide Visual Studio project files Can you blame them? Speaking of awful, impenetrable build systems that don't translate well to other platforms... > MPIR and GMP are *incredibly* complex projects and few people recognise the subtleties which simply don't arise for other types of software. I'm not familiar with writing this type of software, but plenty familiar with building it, and I really don't see a whole lot that goes into a bignum library that doesn't also happen in, say, an optimized BLAS/LAPACK implementation. Of course those are also notorious for having messy and fragile build systems.