我有一个大约一年的ROR应用程序，所以它使用旧版本的多个狂欢依赖项，但我确保它完美无缺，并且在我的本地ubuntu与mysql数据库中没有任何依赖性问题。但是，当我推送到heroku时，我在推动时没有出现任何错误。但是当我将应用程序加载到浏览器时，我收到应用程序错误。
当我运行heroku日志时，这就是我得到的。我不确定导致应用程序崩溃的原因是什么。任何人都可以让我了解可能发生的事情。
2013-07-31T15:33:04.533860+00:00 app[web.1]:
2013-07-31T15:33:24.224146+00:00 app[web.1]: => Booting WEBrick
2013-07-31T15:33:24.224146+00:00 app[web.1]: => Rails 3.1.4 application starting in production on http://0.0.0.0:30818
2013-07-31T15:33:24.224146+00:00 app[web.1]: => Call with -d to detach
2013-07-31T15:33:24.224146+00:00 app[web.1]: => Ctrl-C to shutdown server
2013-07-31T15:33:24.224146+00:00 app[web.1]: Exiting
2013-07-31T15:33:24.225435+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/bundler/gems/spree_email_to_friend-f38187568f33/app/mailers/spree/to_friend_mailer.rb:1:in `<top (required)>'
2013-07-31T15:33:24.225435+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/polyglot-0.3.3/lib/polyglot.rb:63:in `require'
2013-07-31T15:33:24.225435+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/activesupport-3.1.4/lib/active_support/dependencies.rb:240:in `block in require'
2013-07-31T15:33:24.225435+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/activesupport-3.1.4/lib/active_support/dependencies.rb:225:in `load_dependency'
2013-07-31T15:33:24.225801+00:00 app[web.1]: from /app/config/environment.rb:5:in `<top (required)>'
2013-07-31T15:33:24.226233+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/activesupport-3.1.4/lib/active_support/dependencies.rb:240:in `require'
2013-07-31T15:33:24.226392+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/rack-1.3.10/lib/rack/builder.rb:40:in `parse_file'
2013-07-31T15:33:24.225801+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/railties-3.1.4/lib/rails/initializable.rb:55:in `block in run_initializers'
2013-07-31T15:33:24.225435+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/polyglot-0.3.3/lib/polyglot.rb:63:in `require'
2013-07-31T15:33:24.225801+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/railties-3.1.4/lib/rails/application.rb:96:in `initialize!'
2013-07-31T15:33:24.225801+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/railties-3.1.4/lib/rails/railtie/configurable.rb:30:in `method_missing'
2013-07-31T15:33:24.225435+00:00 app[web.1]: /app/vendor/bundle/ruby/1.9.1/bundler/gems/spree_email_to_friend-f38187568f33/app/mailers/spree/to_friend_mailer.rb:2:in `<class:ToFriendMailer>': undefined method `preferred_mails_from' for nil:NilClass (NoMethodError)
2013-07-31T15:33:24.225435+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/activesupport-3.1.4/lib/active_support/dependencies.rb:240:in `require'
2013-07-31T15:33:24.225435+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/activesupport-3.1.4/lib/active_support/dependencies.rb:348:in `require_or_load'
2013-07-31T15:33:24.226392+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/railties-3.1.4/lib/rails/commands.rb:54:in `block in <top (required)>'
2013-07-31T15:33:24.225435+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/activesupport-3.1.4/lib/active_support/dependencies.rb:302:in `depend_on'
2013-07-31T15:33:24.225435+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/activesupport-3.1.4/lib/active_support/dependencies.rb:214:in `require_dependency'
2013-07-31T15:33:24.225801+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/polyglot-0.3.3/lib/polyglot.rb:63:in `require'
2013-07-31T15:33:24.225801+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/railties-3.1.4/lib/rails/initializable.rb:54:in `each'
2013-07-31T15:33:24.226233+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/activesupport-3.1.4/lib/active_support/dependencies.rb:223:in `load_dependency'
2013-07-31T15:33:24.225801+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/polyglot-0.3.3/lib/polyglot.rb:63:in `require'
2013-07-31T15:33:24.225644+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/railties-3.1.4/lib/rails/engine.rb:417:in `block (2 levels) in eager_load!'
2013-07-31T15:33:24.225644+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/railties-3.1.4/lib/rails/engine.rb:416:in `each'
2013-07-31T15:33:24.225644+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/railties-3.1.4/lib/rails/engine.rb:416:in `block in eager_load!'
2013-07-31T15:33:24.225644+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/railties-3.1.4/lib/rails/engine.rb:414:in `each'
2013-07-31T15:33:24.226233+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/rack-1.3.10/lib/rack/builder.rb:51:in `initialize'
2013-07-31T15:33:24.225801+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/activesupport-3.1.4/lib/active_support/dependencies.rb:240:in `block in require'
2013-07-31T15:33:24.226392+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/rack-1.3.10/lib/rack/server.rb:254:in `start'
2013-07-31T15:33:24.226392+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/railties-3.1.4/lib/rails/commands/server.rb:70:in `start'
2013-07-31T15:33:24.226233+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/rack-1.3.10/lib/rack/builder.rb:51:in `instance_eval'
2013-07-31T15:33:24.225644+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/railties-3.1.4/lib/rails/engine.rb:414:in `eager_load!'
2013-07-31T15:33:24.225644+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/railties-3.1.4/lib/rails/application/railties.rb:8:in `each'
2013-07-31T15:33:24.225644+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/railties-3.1.4/lib/rails/application/railties.rb:8:in `all'
2013-07-31T15:33:24.225644+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/railties-3.1.4/lib/rails/engine.rb:412:in `eager_load!'
2013-07-31T15:33:24.226392+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/rack-1.3.10/lib/rack/server.rb:200:in `app'
2013-07-31T15:33:24.226392+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/rack-1.3.10/lib/rack/server.rb:304:in `wrapped_app'
2013-07-31T15:33:24.226392+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/railties-3.1.4/lib/rails/commands.rb:49:in `<top (required)>'
2013-07-31T15:33:24.226392+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/railties-3.1.4/lib/rails/commands/server.rb:46:in `app'
2013-07-31T15:33:24.225644+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/railties-3.1.4/lib/rails/application/finisher.rb:51:in `block in <module:Finisher>'
2013-07-31T15:33:24.225644+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/railties-3.1.4/lib/rails/initializable.rb:30:in `instance_exec'
2013-07-31T15:33:24.225801+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/railties-3.1.4/lib/rails/initializable.rb:30:in `run'
2013-07-31T15:33:24.225801+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/railties-3.1.4/lib/rails/initializable.rb:54:in `run_initializers'
2013-07-31T15:33:24.226392+00:00 app[web.1]: from script/rails:6:in `require'
2013-07-31T15:33:24.226708+00:00 app[web.1]: from script/rails:6:in `<main>'
2013-07-31T15:33:24.226233+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/activesupport-3.1.4/lib/active_support/dependencies.rb:223:in `block in load_dependency'
2013-07-31T15:33:24.226233+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/activesupport-3.1.4/lib/active_support/dependencies.rb:640:in `new_constants_in'
2013-07-31T15:33:24.226233+00:00 app[web.1]: from /app/config.ru:3:in `block in <main>'
2013-07-31T15:33:24.226233+00:00 app[web.1]: from /app/config.ru:in `new'
2013-07-31T15:33:24.226233+00:00 app[web.1]: from /app/config.ru:in `<main>'
2013-07-31T15:33:24.226233+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/rack-1.3.10/lib/rack/builder.rb:40:in `eval'
2013-07-31T15:33:24.226392+00:00 app[web.1]: from /app/vendor/bundle/ruby/1.9.1/gems/railties-3.1.4/lib/rails/commands.rb:49:in `tap'
2013-07-31T15:33:26.428134+00:00 heroku[web.1]: Process exited with status 1
2013-07-31T15:33:26.442115+00:00 heroku[web.1]: State changed from starting to crashed
2013-07-31T15:33:27.208422+00:00 heroku[router]: at=error code=H10 desc="App crashed" method=GET path=/ host=ird.herokuapp.com fwd="115.160.227.226" dyno= connect= service= status=503 bytes=
2013-07-31T15:33:27.645038+00:00 heroku[router]: at=error code=H10 desc="App crashed" method=GET path=/favicon.ico host=ird.herokuapp.com fwd="115.160.227.226" dyno= connect= service= status=503 bytes=