我们有一个应用程序正在从 Bamboo 升级到 Cedar，但我们遇到了一个重大问题。部署顺利进行，但我们立即收到应用程序错误。任何想法表示赞赏。
2012-11-08T19:26:03+00:00 heroku[router]: Error H10 (App crashed) -> GET secure-bayou-3300.herokuapp.com/ dyno= queue= wait= service= status=503 bytes=
2012-11-08T19:26:56+00:00 heroku[web.1]: State changed from crashed to down
2012-11-08T19:26:56+00:00 heroku[web.1]: State changed from down to starting
2012-11-08T19:26:59+00:00 heroku[web.1]: Starting process with command `bundle exec thin start -p 3557 -e production`
2012-11-08T19:27:07+00:00 app[web.1]: >> Using rack adapter
2012-11-08T19:27:07+00:00 app[web.1]: /app/vendor/bundle/ruby/1.9.1/gems/rake-0.9.2.2/lib/rake/ext/module.rb:36:in `const_missing': uninitialized constant Rack::Builder::App (NameError)
2012-11-08T19:27:07+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/aws-s3-0.6.2/lib/aws/s3/extensions.rb:206:in `const_missing_from_s3_library'
2012-11-08T19:27:07+00:00 app[web.1]: from /app/config.ru:9:in `block (2 levels) in <main>'
2012-11-08T19:27:07+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/rack-1.4.1/lib/rack/builder.rb:51:in `instance_eval'
2012-11-08T19:27:07+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/rack-1.4.1/lib/rack/builder.rb:51:in `initialize'
2012-11-08T19:27:07+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/rack-1.4.1/lib/rack/builder.rb:141:in `new'
2012-11-08T19:27:07+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/rack-1.4.1/lib/rack/builder.rb:141:in `block in generate_map'
2012-11-08T19:27:07+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/rack-1.4.1/lib/rack/builder.rb:141:in `each'
2012-11-08T19:27:07+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/rack-1.4.1/lib/rack/builder.rb:141:in `generate_map'
2012-11-08T19:27:07+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/rack-1.4.1/lib/rack/builder.rb:128:in `to_app'
2012-11-08T19:27:07+00:00 app[web.1]: from /app/config.ru:1:in `<main>'
2012-11-08T19:27:07+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/thin-1.5.0/lib/rack/adapter/loader.rb:33:in `eval'
2012-11-08T19:27:07+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/thin-1.5.0/lib/rack/adapter/loader.rb:33:in `load'
2012-11-08T19:27:07+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/thin-1.5.0/lib/rack/adapter/loader.rb:42:in `for'
2012-11-08T19:27:07+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/thin-1.5.0/lib/thin/controllers/controller.rb:169:in `load_adapter'
2012-11-08T19:27:07+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/thin-1.5.0/lib/thin/controllers/controller.rb:73:in `start'
2012-11-08T19:27:07+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/thin-1.5.0/lib/thin/runner.rb:187:in `run_command'
2012-11-08T19:27:07+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/thin-1.5.0/lib/thin/runner.rb:152:in `run!'
2012-11-08T19:27:07+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/thin-1.5.0/bin/thin:6:in `<top (required)>'
2012-11-08T19:27:07+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/bin/thin:19:in `load'
2012-11-08T19:27:07+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/bin/thin:19:in `<main>'
2012-11-08T19:27:08+00:00 heroku[web.1]: Process exited with status 1
2012-11-08T19:27:08+00:00 heroku[web.1]: State changed from starting to crashed