Das Problem ist wie folgt.

Error installing libv8:
ERROR: Failed to build gem native extension.

    D:/Ruby193/bin/ruby.exe extconf.rb
    creating Makefile
    The system can not find the specified path

        D: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 D:Ruby193/lib/ruby/gems/1.9.1/gems/libv8-3.11.8.17/ext/libv8/builder.rb:35:in 'block in build_libv8!'
             from D:Ruby193/lib/ruby/gems/1.9.1/gems/libv8-3.11.8.17/ext/libv8/builder.rb:34:in 'chdir'
             from D:Ruby193/lib/ruby/gems/1.9.1/gems/libv8-3.11.8.17/ext/libv8/builder.rb:34:in 'build_libv8!'
             from D:Ruby193/lib/ruby/gems/1.9.1/gems/libv8-3.11.8.17/ext/libv8/builder.rb:34:in 'install!'
             from extconf.rb:7: in '<main>'
I have installed the python27 and add the path.

python --version
Python 2.7.4

Dann überprüfe ich den Code wie folgt.

 def setup_python!
      # If python v2 cannot be found in PATH,
      # create a symbolic link to python2 the current directory and put it
      # at the head of PATH. That way all commands that inherit this environment
      # will use ./python -> python2
      if python_version !~ /^2/
        unless system 'which python2 2>&1 > /dev/null'
          fail "libv8 requires python 2 to be installed in order to build, but it is currently #{python_version}"
        end
        `ln -fs #{`which python2`.chomp} python`
        ENV['PATH'] = "#{File.expand_path '.'}:#{ENV['PATH']}"
      end
    end

Ich habe versucht, die Linux-Befehlszeile unter Windows zu installieren, damit "ln -fs" funktioniert. Das Problem kann jedoch immer noch nicht behoben werden.