# File lib/bundler/fetcher/compact_index.rb, line 64
      def available?
        return nil unless SharedHelpers.md5_available?
        user_home = Bundler.user_home
        return nil unless user_home.directory? && user_home.writable?
        # Read info file checksums out of /versions, so we can know if gems are up to date
        fetch_uri.scheme != "file" && compact_index_client.update_and_parse_checksums!
      rescue CompactIndexClient::Updater::MisMatchedChecksumError => e
        Bundler.ui.debug(e.message)
        nil
      end