安装rails tutorial的设置安装的spork，最后启动spork的时候死活启动不起来报错如下：
Using RSpecPreloading Rails environmentuninitialized constant ActiveModel::Observing (NameError)/home/sergio/.rvm/gems/ruby-2.0.0-p195/gems/spork-0.9.2/lib/spork/app_framework/rails.rb:56:in `preload_rails'/home/sergio/.rvm/gems/ruby-2.0.0-p195/gems/spork-0.9.2/lib/spork/app_framework/rails.rb:7:in `preload'/home/sergio/.rvm/gems/ruby-2.0.0-p195/gems/spork-0.9.2/lib/spork/test_framework.rb:134:in `block in preload'/home/sergio/.rvm/gems/ruby-2.0.0-p195/gems/spork-0.9.2/lib/spork.rb:62:in `exec_prefork'/home/sergio/.rvm/gems/ruby-2.0.0-p195/gems/spork-0.9.2/lib/spork/test_framework.rb:120:in `preload'/home/sergio/.rvm/gems/ruby-2.0.0-p195/gems/spork-0.9.2/lib/spork/run_strategy/forking.rb:25:in `preload'/home/sergio/.rvm/gems/ruby-2.0.0-p195/gems/spork-0.9.2/lib/spork/runner.rb:74:in `run'/home/sergio/.rvm/gems/ruby-2.0.0-p195/gems/spork-0.9.2/lib/spork/runner.rb:10:in `run'/home/sergio/.rvm/gems/ruby-2.0.0-p195/gems/spork-0.9.2/bin/spork:10:in `'/home/sergio/.rvm/gems/ruby-2.0.0-p195/bin/spork:23:in `load'/home/sergio/.rvm/gems/ruby-2.0.0-p195/bin/spork:23:in `'/home/sergio/.rvm/gems/ruby-2.0.0-p195/bin/ruby_noexec_wrapper:14:in `eval'/home/sergio/.rvm/gems/ruby-2.0.0-p195/bin/ruby_noexec_wrapper:14:in `'real 0m1.925suser 0m1.776ssys 0m0.128s
看了下github，在gem中使用
gem 'spork-rails', github: 'railstutorial/spork-rails'
解决了。。 又是坑
原文地址：rails spork 的坑, 感谢原作者分享。 往往为了自己的不能失败，而处心积虑前怕狼后怕虎，
