Boot Error

Something went wrong while loading app.ru

LoadError: cannot load such file -- haiku

在我尝试运行的应用程序所在的目录中有一个名为haiku.rb的文件,但是在尝试运行程序时出现上述错误.这是代码：

class EnvironmentOutput


  def initialize(app=nil)
    @app = app
  end


  def call(env)
    out = ""

    unless(@app.nil?)
 response = @app.call(env)[2]
 out+=response
end

env.keys.each {|key| out+="<li>#{key}=#{env[key]}</li>"}
["200",{"Content-Type" => "text/html"},[out]]
  end
end

require 'haml'
require 'haiku'

class MyApp
  def call(env)

  poem = Haiku.new.random
  template = File.open("views/index.haml").read
  engine = Haml::Engine.new(template)
  out = engine.render(Object.new,:poem => poem)

   ["200",out]
  end
end

use EnvironmentOutput
run MyApp.new

我确定它是一个小错误,因为代码与教程中的相同,它对他有用…

谢谢