我知道这是一个奇怪的请求，但我是乘客的新手，我无法确定在哪里解决他的错误。 Cap部署到服务器就好了，但即使重启后应用程序也无法启动。我从哪里开始？
此外，这是passenger.log。应用程序development.log完全为空。
我应该添加这是我正在远程访问的ubuntu 12.04服务器。我们使用上限和厨师设置盒子。 如果您想知道，我已经查看过此链接：https://github.com/phusion/passenger/wiki/Debugging-application-startup-problems
deploy@apitest:/home/apps/digest/current/log$ tail -f passenger.log
/home/apps/digest/shared/bundle/ruby/2.0.0/gems/rack-1.5.2/lib/rack/builder.rb:55:in `instance_eval'
/home/apps/digest/shared/bundle/ruby/2.0.0/gems/rack-1.5.2/lib/rack/builder.rb:55:in `initialize'
config.ru:1:in `new'
config.ru:1:in `<main>'
/home/apps/digest/shared/bundle/ruby/2.0.0/gems/passenger-4.0.20/helper-scripts/rack-preloader.rb:105:in `eval'
/home/apps/digest/shared/bundle/ruby/2.0.0/gems/passenger-4.0.20/helper-scripts/rack-preloader.rb:105:in `preload_app'
/home/apps/digest/shared/bundle/ruby/2.0.0/gems/passenger-4.0.20/helper-scripts/rack-preloader.rb:150:in `<module:App>'
/home/apps/digest/shared/bundle/ruby/2.0.0/gems/passenger-4.0.20/helper-scripts/rack-preloader.rb:29:in `<module:PhusionPassenger>'
/home/apps/digest/shared/bundle/ruby/2.0.0/gems/passenger-4.0.20/helper-scripts/rack-preloader.rb:28:in `<main>'
[ 2014-04-17 20:08:52.1202 2620/7f2f2407a700 Pool2/Spawner.h:738 ]: [App 6300 stdout]
[ 2014-04-17 20:08:55.1191 2620/7f2f2407a700 Pool2/Implementation.cpp:849 ]: Could not spawn process for group /home/apps/digest/current#default: An error occured while starting up the preloader.
in 'void Passenger::ApplicationPool2::SmartSpawner::handleErrorResponse(Passenger::ApplicationPool2::SmartSpawner::StartupDetails&)' (SmartSpawner.h:455)
in 'std::string Passenger::ApplicationPool2::SmartSpawner::negotiatePreloaderStartup(Passenger::ApplicationPool2::SmartSpawner::StartupDetails&)' (SmartSpawner.h:558)
in 'void Passenger::ApplicationPool2::SmartSpawner::startPreloader()' (SmartSpawner.h:206)
in 'virtual Passenger::ApplicationPool2::ProcessPtr Passenger::ApplicationPool2::SmartSpawner::spawn(const Passenger::ApplicationPool2::Options&)' (SmartSpawner.h:744)
in 'void Passenger::ApplicationPool2::Group::spawnThreadRealMain(const Passenger::ApplicationPool2::SpawnerPtr&, const Passenger::ApplicationPool2::Options&, unsigned int)' (Implementation.cpp:782)
[ 2014-04-17 20:08:55.1194 2620/7f2f22155700 agents/HelperAgent/RequestHandler.h:1975 ]: [Client 20] Cannot checkout session. An error occured while starting up the preloader.
Error page:
uninitialized constant ActiveModel::Serializer (NameError)
/home/apps/digest/releases/20140418000553/app/serializers/v1/category_serializer.rb:2:in `<module:V1>'
/home/apps/digest/releases/20140418000553/app/serializers/v1/category_serializer.rb:1:in `<top (required)>'
/home/apps/digest/shared/bundle/ruby/2.0.0/gems/railties-4.0.0/lib/rails/engine.rb:465:in `block (2 levels) in eager_load!'
/home/apps/digest/shared/bundle/ruby/2.0.0/gems/railties-4.0.0/lib/rails/engine.rb:464:in `each'
/home/apps/digest/shared/bundle/ruby/2.0.0/gems/railties-4.0.0/lib/rails/engine.rb:464:in `block in eager_load!'
/home/apps/digest/shared/bundle/ruby/2.0.0/gems/railties-4.0.0/lib/rails/engine.rb:462:in `each'
/home/apps/digest/shared/bundle/ruby/2.0.0/gems/railties-4.0.0/lib/rails/engine.rb:462:in `eager_load!'
/home/apps/digest/shared/bundle/ruby/2.0.0/gems/railties-4.0.0/lib/rails/engine.rb:347:in `eager_load!'
/home/apps/digest/shared/bundle/ruby/2.0.0/gems/railties-4.0.0/lib/rails/application/finisher.rb:56:in `each'
/home/apps/digest/shared/bundle/ruby/2.0.0/gems/railties-4.0.0/lib/rails/application/finisher.rb:56:in `block in <module:Finisher>'
/home/apps/digest/shared/bundle/ruby/2.0.0/gems/railties-4.0.0/lib/rails/initializable.rb:30:in `instance_exec'
/home/apps/digest/shared/bundle/ruby/2.0.0/gems/railties-4.0.0/lib/rails/initializable.rb:30:in `run'
/home/apps/digest/shared/bundle/ruby/2.0.0/gems/railties-4.0.0/lib/rails/initializable.rb:55:in `block in run_initializers'
/opt/rbenv/versions/2.0.0-p247/lib/ruby/2.0.0/tsort.rb:150:in `block in tsort_each'
/opt/rbenv/versions/2.0.0-p247/lib/ruby/2.0.0/tsort.rb:183:in `block (2 levels) in each_strongly_connected_component'
/opt/rbenv/versions/2.0.0-p247/lib/ruby/2.0.0/tsort.rb:219:in `each_strongly_connected_component_from'
/opt/rbenv/versions/2.0.0-p247/lib/ruby/2.0.0/tsort.rb:182:in `block in each_strongly_connected_component'
/opt/rbenv/versions/2.0.0-p247/lib/ruby/2.0.0/tsort.rb:180:in `each'
/opt/rbenv/versions/2.0.0-p247/lib/ruby/2.0.0/tsort.rb:180:in `each_strongly_connected_component'
/opt/rbenv/versions/2.0.0-p247/lib/ruby/2.0.0/tsort.rb:148:in `tsort_each'
/home/apps/digest/shared/bundle/ruby/2.0.0/gems/railties-4.0.0/lib/rails/initializable.rb:54:in `run_initializers'
/home/apps/digest/shared/bundle/ruby/2.0.0/gems/railties-4.0.0/lib/rails/application.rb:215:in `initialize!'
/home/apps/digest/shared/bundle/ruby/2.0.0/gems/railties-4.0.0/lib/rails/railtie/configurable.rb:30:in `method_missing'
/home/apps/digest/releases/20140418000553/config/environment.rb:7:in `<top (required)>'
config.ru:3:in `require'
config.ru:3:in `block in <main>'
/home/apps/digest/shared/bundle/ruby/2.0.0/gems/rack-1.5.2/lib/rack/builder.rb:55:in `instance_eval'
/home/apps/digest/shared/bundle/ruby/2.0.0/gems/rack-1.5.2/lib/rack/builder.rb:55:in `initialize'
config.ru:1:in `new'
config.ru:1:in `<main>'
/home/apps/digest/shared/bundle/ruby/2.0.0/gems/passenger-4.0.20/helper-scripts/rack-preloader.rb:105:in `eval'
/home/apps/digest/shared/bundle/ruby/2.0.0/gems/passenger-4.0.20/helper-scripts/rack-preloader.rb:105:in `preload_app'
/home/apps/digest/shared/bundle/ruby/2.0.0/gems/passenger-4.0.20/helper-scripts/rack-preloader.rb:150:in `<module:App>'
/home/apps/digest/shared/bundle/ruby/2.0.0/gems/passenger-4.0.20/helper-scripts/rack-preloader.rb:29:in `<module:PhusionPassenger>'
/home/apps/digest/shared/bundle/ruby/2.0.0/gems/passenger-4.0.20/helper-scripts/rack-preloader.rb:28:in `<main>'
答案 0 :(得分：10)
我注意到：
uninitialized constant ActiveModel::Serializer (NameError)
看起来它没有安装或在Gemfile中。我已经看到这种情况发生（和其他宝石一样）我已经在我的开发盒上本地安装但是忘了包含在Gemfile中。