debug.rb

 create_command 'debug' do
    description 'Debug method call.'

    banner <<-BANNER
      Usage: debug foo(bar)

      step inside method invocation.

    BANNER

    command_options :takes_block => true

    def process
      binding.pry :input => args.first
      target.instance_eval &command_block
      s = "_pry_.input = Readline; #{args.join(" ")}"
      
      binding.pry :input => StringIO.new("#{args.join(" ")}")
      target.instance_eval 
    end

  end

def dummy() 
    binding.pry :input => StringIO.new("step");
    hanoi(3, :a, :b, :c)
end