[Mesa-dev] Cross-compile from Linux to Windows

[Federico Dossena]

I'm sorry to bother you in the dev list but it seems to be the only one 
with activity so it seems like the best place to ask.

I maintain some Mesa builds for Windows. These are builds of libgl-gdi 
with llvmpipe, for both x86 and x86_64; in other words, they're 
opengl32.dll files that users can drop into their game/application to 
have software rendering for OpenGL as a workaround for broken drivers or 
as a fallback for older systems.
I've always used scons on Windows and msvc as a compiler to make these 
builds, but now that scons is being deprecated I've been trying to use 
meson and ninja to cross-compile from Linux (amd64) to Windows (both x86 
and x86_64) without much success. I can get regular Linux builds without 
issues though.

I tried reading the Mesa documentation on cross-compiling but it's very 
minimal and it's partially obsolete so I thought it would be best to ask 
you directly: how do I make these builds? Explain like I'm 5, basically.

Thanks,

Federico