Rscons::Environment.new do |env|
  env["build_root"] = env.build_root
  env["inc_h"] = "inc.h"

  env.Copy("copy_inc.h", "${inc_h}")
  env.depends("${build_root}/program.o", "${inc_h}")
  env.Program("program.exe", ["program.c", "inc.c"])

  env.Command("inc.c",
              [],
              "CMD" => %w[ruby gen.rb ${_TARGET}],
              "CMD_DESC" => "Generating")
  env.produces("inc.c", "inc.h")
end