部署后，我的应用程序今天下午开始崩溃。
这是堆栈：
2013-07-26T17:56:41.137752+00:00 app[web.1]: ** [NewRelic][07/26/13 17:56:41 +0000 b35a7e48-4d93-4e0d-af43-376dec33f34b (2)] INFO : Starting Agent shutdown
2013-07-26T17:56:41.467644+00:00 app[web.1]: /app/vendor/bundle/ruby/1.9.1/gems/activesupport-3.2.13/lib/active_support/dependencies.rb:251:in `require': cannot load such file -- JSON (LoadError)
2013-07-26T17:56:41.467644+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/activesupport-3.2.13/lib/active_support/dependencies.rb:251:in `block in require'
2013-07-26T17:56:41.467644+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/activesupport-3.2.13/lib/active_support/dependencies.rb:251:in `require'
2013-07-26T17:56:41.467644+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/activesupport-3.2.13/lib/active_support/dependencies.rb:236:in `load_dependency'
2013-07-26T17:56:41.467644+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/activesupport-3.2.13/lib/active_support/dependencies.rb:236:in `load_dependency'
2013-07-26T17:56:41.467644+00:00 app[web.1]: from /app/lib/wwtk/device_api.rb:1:in `<top (required)>'
2013-07-26T17:56:41.467644+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/activesupport-3.2.13/lib/active_support/dependencies.rb:251:in `require'
2013-07-26T17:56:41.467644+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/activesupport-3.2.13/lib/active_support/dependencies.rb:251:in `block in require'
2013-07-26T17:56:41.467829+00:00 app[web.1]: from /
app/vendor/bundle/ruby/1.9.1/gems/activesupport-3.2.13/lib/active_support/inflector/methods.rb:230:in `block in constantize'
2013-07-26T17:56:41.467829+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/activesupport-3.2.13/lib/active_support/inflector/methods.rb:229:in `each'
2013-07-26T17:56:41.467644+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/activesupport-3.2.13/lib/active_support/dependencies.rb:251:in `require'
2013-07-26T17:56:41.467644+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/activesupport-3.2.13/lib/active_support/dependencies.rb:359:in `require_or_load'
2013-07-26T17:56:41.467829+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/activesupport-3.2.13/lib/active_support/dependencies.rb:502:in `load_missing_constant'
2013-07-26T17:56:41.467829+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/activesupport-3.2.13/lib/active_support/dependencies.rb:192:in `block in const_missing'
2013-07-26T17:56:41.467829+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/activesupport-3.2.13/lib/active_support/dependencies.rb:190:in `each'
2013-07-26T17:56:41.467829+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/activesupport-3.2.13/lib/active_support/inflector/methods.rb:229:in `constantize'
2013-07-26T17:56:41.467981+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/railties-3.2.13/lib/rails/application/finisher.rb:31:in `block in <module:Finisher>'
2013-07-26T17:56:41.467829+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/activesupport-3.2.13/lib/active_support/dependencies.rb:190:in `const_missing'
2013-07-26T17:56:41.467829+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/activesupport-3.2.13/lib/active_support/dependencies.rb:554:in `get'
2013-07-26T17:56:41.467829+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/actionpack-3.2.13/lib/action_dispatch/middleware/stack.rb:24:in `klass'
2013-07-26T17:56:41.467829+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/actionpack-3.2.13/lib/action_dispatch/middleware/stack.rb:43:in `build'
2013-07-26T17:56:41.467981+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/actionpack-3.2.13/lib/action_dispatch/middleware/stack.rb:113:in `block in build'
2013-07-26T17:56:41.467981+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/actionpack-3.2.13/lib/action_dispatch/middleware/stack.rb:113:in `each'
2013-07-26T17:56:41.467981+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/actionpack-3.2.13/lib/action_dispatch/middleware/stack.rb:113:in `inject'
2013-07-26T17:56:41.468517+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/rack-1.4.5/lib/rack/builder.rb:51:in `initialize'
2013-07-26T17:56:41.468517+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/railties-3.2.13/lib/rails/railtie/configurable.rb:30:in `method_missing'
2013-07-26T17:56:41.468517+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/railties-3.2.13/lib/rails/initializable.rb:54:in `run_initializers'
2013-07-26T17:56:41.468517+00:00 app[web.1]: from /app/config/environment.rb:5:in `<top (required)>'
2013-07-26T17:56:41.468517+00:00 app[web.1]: from config.ru:1:in `<main>'
2013-07-26T17:56:41.468682+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/unicorn-4.6.2/lib/unicorn/http_server.rb:140:in `start'
2013-07-26T17:56:41.468517+00:00 app[web.1]: from config.ru:1:in `new'
2013-07-26T17:56:41.467981+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/railties-3.2.13/lib/rails/initializable.rb:30:in `instance_exec'
2013-07-26T17:56:41.467981+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/actionpack-3.2.13/lib/action_dispatch/middleware/stack.rb:113:in `build'
2013-07-26T17:56:41.467981+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/railties-3.2.13/lib/rails/initializable.rb:30:in `run'
2013-07-26T17:56:41.467981+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/railties-3.2.13/lib/rails/engine.rb:470:in `app'
2013-07-26T17:56:41.467981+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/railties-3.2.13/lib/rails/initializable.rb:54:in `each'
2013-07-26T17:56:41.468517+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/railties-3.2.13/lib/rails/application.rb:136:in `initialize!'
2013-07-26T17:56:41.468517+00:00 app[web.1]: from config.ru:4:in `block in <main>'
2013-07-26T17:56:41.468517+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/rack-1.4.5/lib/rack/builder.rb:51:in `instance_eval'
2013-07-26T17:56:41.467981+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/railties-3.2.13/lib/rails/initializable.rb:55:in `block in run_initializers'
2013-07-26T17:56:41.468682+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/unicorn-4.6.2/lib/unicorn.rb:44:in `block in builder'
2013-07-26T17:56:41.468682+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/unicorn-4.6.2/lib/unicorn/http_server.rb:722:in `call'
2013-07-26T17:56:41.468682+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/unicorn-4.6.2/lib/unicorn/http_server.rb:722:in `build_app!'
2013-07-26T17:56:41.468682+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/unicorn-4.6.2/bin/unicorn:126:in `<top (required)>'
2013-07-26T17:56:41.468517+00:00 app[web.1]: from config.ru:4:in `require'
2013-07-26T17:56:41.468682+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/unicorn-4.6.2/lib/unicorn.rb:44:in `eval'
2013-07-26T17:56:41.468682+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/bin/unicorn:23:in `<main>'
2013-07-26T17:56:41.468682+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/bin/unicorn:23:in `load'
2013-07-26T17:56:43.135205+00:00 heroku[web.1]: State changed from starting to crashed
我们并没有真正改变我们的 Gemfile。
Gemfile.lock 已经包含 json：
> grep json Gemfile.lock
multi_json (~> 1.0)
multi_json (~> 1.0)
json
json (1.8.0)
multi_json (>= 1.5)
multi_json (1.7.6)
multi_json (~> 1.0)
multi_json (~> 1.3)
json (~> 1.4)
multi_json (~> 1.0)
multi_json (~> 1.0)
multi_json (~> 1.0, >= 1.0.2)
我尝试重新启动应用程序或使用 heroku repo:purge_cache。没有任何帮助。