以前やった手順でWindowsにRubyInstaller,EVELOPMENT KITをインストールした状態で、bundleでibv8を入れようとしたところ以下のようなエラーが出た C:/Ruby193/lib/ruby/gems/1.9.1/gems/libv8-3.11.8.17/ext/libv8/builder.rb:49:in `setup_python!': libv8 requires python 2 to be installed in order to build, but it is currently not available (RuntimeError) from C:/Ruby193/lib/ruby/gems/1.9.1/gems/libv8-3.11.8.17/ext/libv8/builder.rb:35:in `block in build_libv