ActionMailer方法缺少「default_url_setting」

Question

當我在開發模式下運行我的rails應用程序時，它運行良好。當我在生產模式下運行，但是，它崩潰的推出，我從服務器獲取此輸出：

/Users/user/.rvm/gems/ruby-1.9.3-p0/gems/actionmailer-3.2.3/lib/action_mailer/base.rb:437:in `method_missing': undefined method `default_url_setting=' for ActionMailer::Base:Class (NoMethodError) 
from /Users/user/.rvm/gems/ruby-1.9.3-p0/gems/actionmailer-3.2.3/lib/action_mailer/railtie.rb:34:in `block (3 levels) in <class:Railtie>' 
from /Users/user/.rvm/gems/ruby-1.9.3-p0/gems/actionmailer-3.2.3/lib/action_mailer/railtie.rb:34:in `each' 
from /Users/user/.rvm/gems/ruby-1.9.3-p0/gems/actionmailer-3.2.3/lib/action_mailer/railtie.rb:34:in `block (2 levels) in <class:Railtie>' 
from /Users/user/.rvm/gems/ruby-1.9.3-p0/gems/activesupport-3.2.3/lib/active_support/lazy_load_hooks.rb:36:in `instance_eval' 
from /Users/user/.rvm/gems/ruby-1.9.3-p0/gems/activesupport-3.2.3/lib/active_support/lazy_load_hooks.rb:36:in `execute_hook' 
from /Users/user/.rvm/gems/ruby-1.9.3-p0/gems/activesupport-3.2.3/lib/active_support/lazy_load_hooks.rb:43:in `block in run_load_hooks' 
from /Users/user/.rvm/gems/ruby-1.9.3-p0/gems/activesupport-3.2.3/lib/active_support/lazy_load_hooks.rb:42:in `each' 
from /Users/user/.rvm/gems/ruby-1.9.3-p0/gems/activesupport-3.2.3/lib/active_support/lazy_load_hooks.rb:42:in `run_load_hooks' 
from /Users/user/.rvm/gems/ruby-1.9.3-p0/gems/actionmailer-3.2.3/lib/action_mailer/base.rb:733:in `<class:Base>' 
from /Users/user/.rvm/gems/ruby-1.9.3-p0/gems/actionmailer-3.2.3/lib/action_mailer/base.rb:325:in `<module:ActionMailer>' 
from /Users/user/.rvm/gems/ruby-1.9.3-p0/gems/actionmailer-3.2.3/lib/action_mailer/base.rb:10:in `<top (required)>' 
from /Users/user/Desktop/MetaRepo/MetaWebsite/app/mailers/notification_mailer.rb:1:in `<top (required)>' 
from /Users/user/.rvm/gems/ruby-1.9.3-p0/gems/activesupport-3.2.3/lib/active_support/dependencies.rb:251:in `require' 
from /Users/user/.rvm/gems/ruby-1.9.3-p0/gems/activesupport-3.2.3/lib/active_support/dependencies.rb:251:in `block in require' 
from /Users/user/.rvm/gems/ruby-1.9.3-p0/gems/activesupport-3.2.3/lib/active_support/dependencies.rb:236:in `load_dependency' 
from /Users/user/.rvm/gems/ruby-1.9.3-p0/gems/activesupport-3.2.3/lib/active_support/dependencies.rb:251:in `require' 
from /Users/user/.rvm/gems/ruby-1.9.3-p0/gems/activesupport-3.2.3/lib/active_support/dependencies.rb:359:in `require_or_load' 
from /Users/user/.rvm/gems/ruby-1.9.3-p0/gems/activesupport-3.2.3/lib/active_support/dependencies.rb:313:in `depend_on' 
from /Users/user/.rvm/gems/ruby-1.9.3-p0/gems/activesupport-3.2.3/lib/active_support/dependencies.rb:225:in `require_dependency' 
from /Users/user/.rvm/gems/ruby-1.9.3-p0/gems/railties-3.2.3/lib/rails/engine.rb:439:in `block (2 levels) in eager_load!' 
from /Users/user/.rvm/gems/ruby-1.9.3-p0/gems/railties-3.2.3/lib/rails/engine.rb:438:in `each' 
from /Users/user/.rvm/gems/ruby-1.9.3-p0/gems/railties-3.2.3/lib/rails/engine.rb:438:in `block in eager_load!' 
from /Users/user/.rvm/gems/ruby-1.9.3-p0/gems/railties-3.2.3/lib/rails/engine.rb:436:in `each' 
from /Users/user/.rvm/gems/ruby-1.9.3-p0/gems/railties-3.2.3/lib/rails/engine.rb:436:in `eager_load!' 
from /Users/user/.rvm/gems/ruby-1.9.3-p0/gems/railties-3.2.3/lib/rails/application/finisher.rb:53:in `block in <module:Finisher>' 
from /Users/user/.rvm/gems/ruby-1.9.3-p0/gems/railties-3.2.3/lib/rails/initializable.rb:30:in `instance_exec' 
from /Users/user/.rvm/gems/ruby-1.9.3-p0/gems/railties-3.2.3/lib/rails/initializable.rb:30:in `run' 
from /Users/user/.rvm/gems/ruby-1.9.3-p0/gems/railties-3.2.3/lib/rails/initializable.rb:55:in `block in run_initializers' 
from /Users/user/.rvm/gems/ruby-1.9.3-p0/gems/railties-3.2.3/lib/rails/initializable.rb:54:in `each' 
from /Users/user/.rvm/gems/ruby-1.9.3-p0/gems/railties-3.2.3/lib/rails/initializable.rb:54:in `run_initializers' 
from /Users/user/.rvm/gems/ruby-1.9.3-p0/gems/railties-3.2.3/lib/rails/application.rb:136:in `initialize!' 
from /Users/user/.rvm/gems/ruby-1.9.3-p0/gems/railties-3.2.3/lib/rails/railtie/configurable.rb:30:in `method_missing' 
from /Users/user/Desktop/MetaRepo/MetaWebsite/config/environment.rb:5:in `<top (required)>' 
from /Users/user/Desktop/MetaRepo/MetaWebsite/config.ru:4:in `require' 
from /Users/user/Desktop/MetaRepo/MetaWebsite/config.ru:4:in `block in <main>' 
from /Users/user/.rvm/gems/ruby-1.9.3-p0/gems/rack-1.4.1/lib/rack/builder.rb:51:in `instance_eval' 
from /Users/user/.rvm/gems/ruby-1.9.3-p0/gems/rack-1.4.1/lib/rack/builder.rb:51:in `initialize' 
from /Users/user/Desktop/MetaRepo/MetaWebsite/config.ru:1:in `new' 
from /Users/user/Desktop/MetaRepo/MetaWebsite/config.ru:1:in `<main>' 
from /Users/user/.rvm/gems/ruby-1.9.3-p0/gems/rack-1.4.1/lib/rack/builder.rb:40:in `eval' 
from /Users/user/.rvm/gems/ruby-1.9.3-p0/gems/rack-1.4.1/lib/rack/builder.rb:40:in `parse_file' 
from /Users/user/.rvm/gems/ruby-1.9.3-p0/gems/rack-1.4.1/lib/rack/server.rb:200:in `app' 
from /Users/user/.rvm/gems/ruby-1.9.3-p0/gems/railties-3.2.3/lib/rails/commands/server.rb:46:in `app' 
from /Users/user/.rvm/gems/ruby-1.9.3-p0/gems/rack-1.4.1/lib/rack/server.rb:301:in `wrapped_app' 
from /Users/user/.rvm/gems/ruby-1.9.3-p0/gems/rack-1.4.1/lib/rack/server.rb:252:in `start' 
from /Users/user/.rvm/gems/ruby-1.9.3-p0/gems/railties-3.2.3/lib/rails/commands/server.rb:70:in `start' 
from /Users/user/.rvm/gems/ruby-1.9.3-p0/gems/railties-3.2.3/lib/rails/commands.rb:55:in `block in <top (required)>' 
from /Users/user/.rvm/gems/ruby-1.9.3-p0/gems/railties-3.2.3/lib/rails/commands.rb:50:in `tap' 
from /Users/user/.rvm/gems/ruby-1.9.3-p0/gems/railties-3.2.3/lib/rails/commands.rb:50:in `<top (required)>' 
from script/rails:6:in `require' 
from script/rails:6:in `<main>' 

顯然它是與我的ActionMailer寶石，但我完全難倒。任何幫助深表感謝！

Answer 1

在documentation（ctrl + F「default_url」），有default_url_options。也許你拼錯了這個方法？

config.action_mailer.default_url_options = { :host => "example.com" }