to_s

# File lib/bundler/source/git.rb, line 62
      def to_s
        at = if local?
          path
        elsif user_ref = options["ref"]
          if ref =~ /\A[a-z0-9]{4,}\z/
            shortref_for_display(user_ref)
          else
            user_ref
          end
        else
          ref
        end

        rev = begin
                "@#{shortref_for_display(revision)}"
              rescue GitError
                nil
              end

        "#{@safe_uri} (at #{at}#{rev})"
      end