Gem::Installer#write_build_info_file

# File tmp/rubies/ruby-3.0.5/lib/rubygems/installer.rb, line 921
def write_build_info_file
  return if build_args.empty?

  build_info_dir = File.join gem_home, 'build_info'

  dir_mode = options[:dir_mode]
  FileUtils.mkdir_p build_info_dir, :mode => dir_mode && 0755

  build_info_file = File.join build_info_dir, "#{spec.full_name}.info"

  File.open build_info_file, 'w' do |io|
    build_args.each do |arg|
      io.puts arg
    end
  end

  File.chmod(dir_mode, build_info_dir) if dir_mode
end