MRuby::Gem::Specification.new() do
spec.author =
spec.license =
spec.summary =
spec.homepage =
spec.build.defines <<
#spec.build.linker.libraries << 'gmp' # when uses libgmp
spec.build.libmruby_core_objs << Dir.glob(File.join(__dir__, )).map {
objfile(fn.relative_path_from(__dir__).pathmap())
}
end