class Gem::Indexer

def update_specs_index(index, source, dest)
  specs_index = Marshal.load Gem.read_binary(source)
  index.each do |spec|
    platform = spec.original_platform
    platform = Gem::Platform::RUBY if platform.nil? or platform.empty?
    specs_index << [spec.name, spec.version, platform]
  end
  specs_index = compact_specs specs_index.uniq.sort
  open dest, 'wb' do |io|
    Marshal.dump specs_index, io
  end
end