# File lib/buildr/packaging/artifact.rb, line 326
      def to_spec(hash)
        hash = to_hash(hash) unless Hash === hash
        version = ":#{hash[:version]}" if hash[:version]
        classifier = ":#{hash[:classifier]}" if hash[:classifier]
        "#{hash[:group]}:#{hash[:id]}:#{hash[:type] || DEFAULT_TYPE}#{classifier}#{version}"
      end