Rails 3.2 ActionMailer演示失败

Question

我已经使用rails 3很长一段时间了，但是我现在还没有使用ActionMailer。我跟着guide，并预计它可以开箱即用。但是，似乎我碰到了深入内部导轨代码的一些错误。不幸的是，我找不到任何提及这个错误的信息，我猜测它必须做到配置。

我的邮件类是：

class UserMailer < ActionMailer::Base 
    default :from => "notifications@example.com" 

    def welcome_email 
    @url = "http://example.com/login" 
    mail(:to => "test@example.com", :subject => "Welcome to My Awesome Site") 
    end 
end 

当我尝试使用邮件，我得到：

UserMailer.welcome_email 
NoMethodError: undefined method `protected_instance_variables=' for ActionController::Base:Class 
    from /Users/user/.rvm/gems/ruby-1.9.2-p0/gems/actionpack-3.2.1/lib/action_controller/metal/compatibility.rb:22:in `block in <module:Compatibility>' 
    from /Users/user/.rvm/gems/ruby-1.9.2-p0/gems/activesupport-3.2.1/lib/active_support/concern.rb:117:in `class_eval' 
    from /Users/user/.rvm/gems/ruby-1.9.2-p0/gems/activesupport-3.2.1/lib/active_support/concern.rb:117:in `append_features' 
    from /Users/user/.rvm/gems/ruby-1.9.2-p0/gems/actionpack-3.2.1/lib/action_controller/base.rb:232:in `include' 
    from /Users/user/.rvm/gems/ruby-1.9.2-p0/gems/actionpack-3.2.1/lib/action_controller/base.rb:232:in `<class:Base>' 
    from /Users/user/.rvm/gems/ruby-1.9.2-p0/gems/actionpack-3.2.1/lib/action_controller/base.rb:171:in `<module:ActionController>' 
    from /Users/user/.rvm/gems/ruby-1.9.2-p0/gems/actionpack-3.2.1/lib/action_controller/base.rb:3:in `<top (required)>' 
    from /Users/user/.rvm/gems/ruby-1.9.2-p0/gems/actionpack-3.2.1/lib/action_view/test_case.rb:11:in `<class:TestCase>' 
    from /Users/user/.rvm/gems/ruby-1.9.2-p0/gems/actionpack-3.2.1/lib/action_view/test_case.rb:10:in `<module:ActionView>' 
    from /Users/user/.rvm/gems/ruby-1.9.2-p0/gems/actionpack-3.2.1/lib/action_view/test_case.rb:8:in `<top (required)>' 
    from /Users/user/.rvm/gems/ruby-1.9.2-p0/gems/prototype-rails-3.2.1/lib/prototype-rails/on_load_action_view.rb:17:in `<top (required)>' 
    from /Users/user/.rvm/gems/ruby-1.9.2-p0/gems/activesupport-3.2.1/lib/active_support/dependencies.rb:251:in `require' 
    from /Users/user/.rvm/gems/ruby-1.9.2-p0/gems/activesupport-3.2.1/lib/active_support/dependencies.rb:251:in `block in require' 
    from /Users/user/.rvm/gems/ruby-1.9.2-p0/gems/activesupport-3.2.1/lib/active_support/dependencies.rb:234:in `block in load_dependency' 
    from /Users/user/.rvm/gems/ruby-1.9.2-p0/gems/activesupport-3.2.1/lib/active_support/dependencies.rb:639:in `new_constants_in' 
    from /Users/user/.rvm/gems/ruby-1.9.2-p0/gems/activesupport-3.2.1/lib/active_support/dependencies.rb:234:in `load_dependency' 
... 23 levels... 
    from /users/user/Documents/element/app/mailers/user_mailer.rb:1:in `<top (required)>' 
    from /Users/user/.rvm/gems/ruby-1.9.2-p0/gems/activesupport-3.2.1/lib/active_support/dependencies.rb:469:in `load' 
    from /Users/user/.rvm/gems/ruby-1.9.2-p0/gems/activesupport-3.2.1/lib/active_support/dependencies.rb:469:in `block in load_file' 
    from /Users/user/.rvm/gems/ruby-1.9.2-p0/gems/activesupport-3.2.1/lib/active_support/dependencies.rb:639:in `new_constants_in' 
    from /Users/user/.rvm/gems/ruby-1.9.2-p0/gems/activesupport-3.2.1/lib/active_support/dependencies.rb:468:in `load_file' 
    from /Users/user/.rvm/gems/ruby-1.9.2-p0/gems/activesupport-3.2.1/lib/active_support/dependencies.rb:353:in `require_or_load' 
    from /Users/user/.rvm/gems/ruby-1.9.2-p0/gems/activesupport-3.2.1/lib/active_support/dependencies.rb:502:in `load_missing_constant' 
    from /Users/user/.rvm/gems/ruby-1.9.2-p0/gems/activesupport-3.2.1/lib/active_support/dependencies.rb:192:in `block in const_missing' 
    from /Users/user/.rvm/gems/ruby-1.9.2-p0/gems/activesupport-3.2.1/lib/active_support/dependencies.rb:190:in `each' 
    from /Users/user/.rvm/gems/ruby-1.9.2-p0/gems/activesupport-3.2.1/lib/active_support/dependencies.rb:190:in `const_missing' 
    from (irb):1 
    from /Users/user/.rvm/gems/ruby-1.9.2-p0/gems/railties-3.2.1/lib/rails/commands/console.rb:47:in `start' 
    from /Users/user/.rvm/gems/ruby-1.9.2-p0/gems/railties-3.2.1/lib/rails/commands/console.rb:8:in `start' 
    from /Users/user/.rvm/gems/ruby-1.9.2-p0/gems/railties-3.2.1/lib/rails/commands.rb:41:in `<top (required)>' 
    from script/rails:6:in `require' 
    from script/rails:6:in `<main>' 

我使用的铁轨3.2.1。我看到一些提及protected_instance_variables =被弃用的情况，这也许可以解释为什么它没有为ActionController :: Base定义。但是，这看起来像是一个轨道错误，我会想象，ActionMailer已经过很好的测试。有人有主意吗？

感谢

Answer 1

我曾经历过上启动我的Rails 3.2.1应用类似的错误 - 移除了原型轨宝石解决了这个问题对我来说。

当然，我碰巧使用的是原型，所以现在有一个不同的问题需要解决。