module RbSys::Mkmf

def env_vars(builder)
  lines = builder.build_env.map { |k, v| env_line(k, v) }
  lines << env_line("CC", env_or_makefile_config("CC"))
  lines << env_line("CXX", env_or_makefile_config("CXX"))
  lines << env_line("AR", env_or_makefile_config("AR")) unless env_or_makefile_config("AR") == "libtool -static"
  lines.compact.join("\n")
end