我正在学习 Ruby on Rails 教程。在第 5 章中，我遇到了另一个我无法弄清楚也找不到解决方案的障碍。
一方面，我的主页消失了，我不知道为什么。也就是说，由于某种原因，无法访问它。
当我运行测试时。我得到以下回复：
遇到异常：RuntimeError：应用程序已被初始化。回溯：
有人可以帮忙吗？
这是回溯（带有一些有用的格式以便于查看）：
/Users/tomgalpin/.rvm/gems/ruby-1.9.3-p194@rails3tutorial2ndEd/gems/railties-3.2.8/lib/rails/application.rb:135:in `initialize!'
/Users/tomgalpin/.rvm/gems/ruby-1.9.3-p194@rails3tutorial2ndEd/gems/railties-3.2.8/lib/rails/railtie/configurable.rb:30:in `method_missing'
/Users/tomgalpin/rails_projects/sample_app/config/environment.rb:5:in `<top (required)>'
/Users/tomgalpin/.rvm/gems/ruby-1.9.3-p194@rails3tutorial2ndEd/gems/activesupport-3.2.8/lib/active_support/dependencies.rb:251:in `require'
/Users/tomgalpin/.rvm/gems/ruby-1.9.3-p194@rails3tutorial2ndEd/gems/activesupport-3.2.8/lib/active_support/dependencies.rb:251:in `block in require'
/Users/tomgalpin/.rvm/gems/ruby-1.9.3-p194@rails3tutorial2ndEd/gems/activesupport-3.2.8/lib/active_support/dependencies.rb:236:in `load_dependency'
/Users/tomgalpin/.rvm/gems/ruby-1.9.3-p194@rails3tutorial2ndEd/gems/activesupport-3.2.8/lib/active_support/dependencies.rb:251:in `require'
/Users/tomgalpin/rails_projects/sample_app/spec/spec_helper.rb:3:in `<top (required)>'
/Users/tomgalpin/.rvm/gems/ruby-1.9.3-p194@rails3tutorial2ndEd/gems/activesupport-3.2.8/lib/active_support/dependencies.rb:245:in `load'
/Users/tomgalpin/.rvm/gems/ruby-1.9.3-p194@rails3tutorial2ndEd/gems/activesupport-3.2.8/lib/active_support/dependencies.rb:245:in `block in load'
/Users/tomgalpin/.rvm/gems/ruby-1.9.3-p194@rails3tutorial2ndEd/gems/activesupport-3.2.8/lib/active_support/dependencies.rb:236:in `load_dependency'
/Users/tomgalpin/.rvm/gems/ruby-1.9.3-p194@rails3tutorial2ndEd/gems/activesupport-3.2.8/lib/active_support/dependencies.rb:245:in `load'
/Users/tomgalpin/.rvm/gems/ruby-1.9.3-p194@rails3tutorial2ndEd/gems/spork-0.9.2/lib/spork/run_strategy/forking.rb:11:in `block in run'
/Users/tomgalpin/.rvm/gems/ruby-1.9.3-p194@rails3tutorial2ndEd/gems/spork-0.9.2/lib/spork/forker.rb:21:in `block in initialize'
/Users/tomgalpin/.rvm/gems/ruby-1.9.3-p194@rails3tutorial2ndEd/gems/spork-0.9.2/lib/spork/forker.rb:18:in `fork'
/Users/tomgalpin/.rvm/gems/ruby-1.9.3-p194@rails3tutorial2ndEd/gems/spork-0.9.2/lib/spork/forker.rb:18:in `initialize'
/Users/tomgalpin/.rvm/gems/ruby-1.9.3-p194@rails3tutorial2ndEd/gems/spork-0.9.2/lib/spork/run_strategy/forking.rb:9:in `new'
/Users/tomgalpin/.rvm/gems/ruby-1.9.3-p194@rails3tutorial2ndEd/gems/spork-0.9.2/lib/spork/run_strategy/forking.rb:9:in `run'
/Users/tomgalpin/.rvm/gems/ruby-1.9.3-p194@rails3tutorial2ndEd/gems/spork-0.9.2/lib/spork/server.rb:48:in `run'
/Users/tomgalpin/.rvm/rubies/ruby-1.9.3-p194/lib/ruby/1.9.1/drb/drb.rb:1548:in `perform_without_block'
/Users/tomgalpin/.rvm/rubies/ruby-1.9.3-p194/lib/ruby/1.9.1/drb/drb.rb:1508:in `perform'
/Users/tomgalpin/.rvm/rubies/ruby-1.9.3-p194/lib/ruby/1.9.1/drb/drb.rb:1586:in `block (2 levels) in main_loop'
/Users/tomgalpin/.rvm/rubies/ruby-1.9.3-p194/lib/ruby/1.9.1/drb/drb.rb:1582:in `loop'
/Users/tomgalpin/.rvm/rubies/ruby-1.9.3-p194/lib/ruby/1.9.1/drb/drb.rb:1582:in `block in main_loop'