build do Environment.new(echo: :command) do |env| tempdir = ENV["TEMP"] || ENV["TMP"] || "/tmp" source_file = File.join(tempdir, "abs.c") File.open(source_file, "w") do |fh| fh.puts(<<-EOF) int main() { return 29; } EOF end env.Program("abs.exe", source_file) end end