This image contains everything you need to create a windows bundles from msys2 packages. It was built to help with Pidgin3 development as most of use tend to use Linux and don't readily have a Windows machine available.
This image uses pacman-static and a bunch of helper files from mingw64-base to make this all work.
It setups up a new empty root in /windows which can be modified using
pacman-cross which just runs pacman --root /windows $@. After installing
packages you can extract the files by any means you like from
/windows/mingw32 or /windows/mingw64 depending on which packages you
installed.
There is also a makepkg-cross that will allow you to build packages. It
requires you set the MINGW_PACKAGE_PREFIX environment variable to the
correct value. As far as I know, the only options are mingw-w64-i686 and
mingw-w64-x86_64. So a simple invocation like the following from the
directory containing your PKGBUILD will spit out a package for you.
MINGW_PACKAGE_PREFIX=mingw-w64-i686 makepkg-cross
This image was built to be run in convey pipelines, but can we used where ever.