def load_specs(source_uri, file)
    file_name  = "#{file}.#{Gem.marshal_version}"
    spec_path  = source_uri + "#{file_name}.gz"
    cache_dir  = cache_dir spec_path
    local_file = File.join(cache_dir, file_name)
    loaded     = false

    if File.exist? local_file then
      begin
        spec_dump =
          @fetcher.fetch_path(spec_path, File.mtime(local_file))
      rescue Gem::RemoteFetcher::FetchError => e
        alert_warning "Error fetching data: #{e.message}"
      end

      loaded = true if spec_dump

      spec_dump ||= Gem.read_binary local_file
    else
      spec_dump = @fetcher.fetch_path spec_path
      loaded = true
    end

    specs = begin
              Marshal.load spec_dump
            rescue ArgumentError
              spec_dump = @fetcher.fetch_path spec_path
              loaded = true

              Marshal.load spec_dump
            end

    if loaded and @update_cache then
      begin
        FileUtils.mkdir_p cache_dir

        open local_file, 'wb' do |io|
          io << spec_dump
        end
      rescue
      end
    end

    specs
  end
#
Loads specs in +file+, fetching from +source_uri+ if the on-disk cache is
out of date.