これらのDeviseエラーの原因は何ですか？私はこのようなセットアップ<a href="https://github.com/plataformatec/devise" rel="nofollow">Devise</a>にしようとしています

Question

：

$ rails generate devise:install 
... 
$ rails generate devise User 
... 
$ rake db:migrate --stack 

rake db:migrate --stackラインは、このエラーが発生します。私はコメントアウトした場合

class User < ActiveRecord::Base 
    # Include default devise modules. Others available are: 
    # :token_authenticatable, :confirmable, :lockable and :timeoutable 
    devise :database_authenticatable, :registerable, 
     :recoverable, :rememberable, :trackable, :validatable 

    # Setup accessible (or protected) attributes for your model 
    attr_accessible :email, :password, :password_confirmation, :remember_me 
end 

：

WARNING: Global access to Rake DSL methods is deprecated. Please include 
    ... Rake::DSL into classes and modules which use the Rake DSL methods. 
WARNING: DSL method Elephant::Application#task called at /Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/railties-3.0.1/lib/rails/application.rb:214:in `initialize_tasks' 
** Invoke db:migrate (first_time) 
** Invoke environment (first_time) 
** Execute environment 
rake aborted! 
undefined method `devise' for User(Table doesn't exist):Class 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/activerecord-3.0.1/lib/active_record/base.rb:1016:in `method_missing' 
/Users/ben/rails_projects/elephant/app/models/user.rb:4:in `<class:User>' 
/Users/ben/rails_projects/elephant/app/models/user.rb:1:in `<top (required)>' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/activesupport-3.0.1/lib/active_support/dependencies.rb:454:in `load' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/activesupport-3.0.1/lib/active_support/dependencies.rb:454:in `block in load_file' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/activesupport-3.0.1/lib/active_support/dependencies.rb:591:in `new_constants_in' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/activesupport-3.0.1/lib/active_support/dependencies.rb:453:in `load_file' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/activesupport-3.0.1/lib/active_support/dependencies.rb:340:in `require_or_load' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/activesupport-3.0.1/lib/active_support/dependencies.rb:491:in `load_missing_constant' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/activesupport-3.0.1/lib/active_support/dependencies.rb:183:in `block in const_missing' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/activesupport-3.0.1/lib/active_support/dependencies.rb:181:in `each' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/activesupport-3.0.1/lib/active_support/dependencies.rb:181:in `const_missing' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/activesupport-3.0.1/lib/active_support/inflector/methods.rb:124:in `block in constantize' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/activesupport-3.0.1/lib/active_support/inflector/methods.rb:123:in `each' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/activesupport-3.0.1/lib/active_support/inflector/methods.rb:123:in `constantize' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/activesupport-3.0.1/lib/active_support/dependencies.rb:523:in `block in <class:Reference>' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/activesupport-3.0.1/lib/active_support/dependencies.rb:533:in `yield' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/activesupport-3.0.1/lib/active_support/dependencies.rb:533:in `default' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/activesupport-3.0.1/lib/active_support/dependencies.rb:533:in `get' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/devise-1.1.5/lib/devise/mapping.rb:69:in `to' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/devise-1.1.5/lib/devise/mapping.rb:64:in `modules' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/devise-1.1.5/lib/devise/mapping.rb:73:in `strategies' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/devise-1.1.5/lib/devise.rb:281:in `block in configure_warden!' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/devise-1.1.5/lib/devise.rb:280:in `each_value' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/devise-1.1.5/lib/devise.rb:280:in `configure_warden!' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/devise-1.1.5/lib/devise/rails/routes.rb:7:in `finalize_with_devise!' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/railties-3.0.1/lib/rails/application.rb:128:in `block in reload_routes!' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/activesupport-3.0.1/lib/active_support/lazy_load_hooks.rb:36:in `instance_eval' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/activesupport-3.0.1/lib/active_support/lazy_load_hooks.rb:36:in `execute_hook' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/activesupport-3.0.1/lib/active_support/lazy_load_hooks.rb:26:in `on_load' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/railties-3.0.1/lib/rails/application.rb:128:in `reload_routes!' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/railties-3.0.1/lib/rails/application.rb:120:in `block in routes_reloader' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/activesupport-3.0.1/lib/active_support/file_update_checker.rb:32:in `call' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/activesupport-3.0.1/lib/active_support/file_update_checker.rb:32:in `execute_if_updated' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/actionpack-3.0.1/lib/action_dispatch/railtie.rb:14:in `block (2 levels) in <class:Railtie>' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/activesupport-3.0.1/lib/active_support/callbacks.rb:419:in `_run_prepare_callbacks' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/actionpack-3.0.1/lib/action_dispatch/middleware/callbacks.rb:40:in `initialize' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/actionpack-3.0.1/lib/action_dispatch/middleware/stack.rb:33:in `new' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/actionpack-3.0.1/lib/action_dispatch/middleware/stack.rb:33:in `build' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/actionpack-3.0.1/lib/action_dispatch/middleware/stack.rb:79:in `block in build' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/actionpack-3.0.1/lib/action_dispatch/middleware/stack.rb:79:in `each' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/actionpack-3.0.1/lib/action_dispatch/middleware/stack.rb:79:in `inject' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/actionpack-3.0.1/lib/action_dispatch/middleware/stack.rb:79:in `build' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/railties-3.0.1/lib/rails/application.rb:162:in `app' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/railties-3.0.1/lib/rails/application/finisher.rb:35:in `block in <module:Finisher>' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/railties-3.0.1/lib/rails/initializable.rb:25:in `instance_exec' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/railties-3.0.1/lib/rails/initializable.rb:25:in `run' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/railties-3.0.1/lib/rails/initializable.rb:50:in `block in run_initializers' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/railties-3.0.1/lib/rails/initializable.rb:49:in `each' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/railties-3.0.1/lib/rails/initializable.rb:49:in `run_initializers' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/railties-3.0.1/lib/rails/application.rb:134:in `initialize!' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/railties-3.0.1/lib/rails/application.rb:77:in `method_missing' 
/Users/ben/rails_projects/elephant/config/environment.rb:5:in `<top (required)>' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/activesupport-3.0.1/lib/active_support/dependencies.rb:239:in `require' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/activesupport-3.0.1/lib/active_support/dependencies.rb:239:in `block in require' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/activesupport-3.0.1/lib/active_support/dependencies.rb:225:in `block in load_dependency' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/activesupport-3.0.1/lib/active_support/dependencies.rb:591:in `new_constants_in' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/activesupport-3.0.1/lib/active_support/dependencies.rb:225:in `load_dependency' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/activesupport-3.0.1/lib/active_support/dependencies.rb:239:in `require' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/railties-3.0.1/lib/rails/application.rb:103:in `require_environment!' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/railties-3.0.1/lib/rails/application.rb:216:in `block in initialize_tasks' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/rake-0.9.2/lib/rake/task.rb:205:in `call' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/rake-0.9.2/lib/rake/task.rb:205:in `block in execute' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/rake-0.9.2/lib/rake/task.rb:200:in `each' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/rake-0.9.2/lib/rake/task.rb:200:in `execute' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/rake-0.9.2/lib/rake/task.rb:158:in `block in invoke_with_call_chain' 
/Users/ben/.rvm/rubies/ruby-1.9.2-p0/lib/ruby/1.9.1/monitor.rb:201:in `mon_synchronize' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/rake-0.9.2/lib/rake/task.rb:151:in `invoke_with_call_chain' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/rake-0.9.2/lib/rake/task.rb:176:in `block in invoke_prerequisites' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/rake-0.9.2/lib/rake/task.rb:174:in `each' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/rake-0.9.2/lib/rake/task.rb:174:in `invoke_prerequisites' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/rake-0.9.2/lib/rake/task.rb:157:in `block in invoke_with_call_chain' 
/Users/ben/.rvm/rubies/ruby-1.9.2-p0/lib/ruby/1.9.1/monitor.rb:201:in `mon_synchronize' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/rake-0.9.2/lib/rake/task.rb:151:in `invoke_with_call_chain' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/rake-0.9.2/lib/rake/task.rb:144:in `invoke' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/rake-0.9.2/lib/rake/application.rb:112:in `invoke_task' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/rake-0.9.2/lib/rake/application.rb:90:in `block (2 levels) in top_level' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/rake-0.9.2/lib/rake/application.rb:90:in `each' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/rake-0.9.2/lib/rake/application.rb:90:in `block in top_level' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/rake-0.9.2/lib/rake/application.rb:129:in `standard_exception_handling' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/rake-0.9.2/lib/rake/application.rb:84:in `top_level' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/rake-0.9.2/lib/rake/application.rb:62:in `block in run' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/rake-0.9.2/lib/rake/application.rb:129:in `standard_exception_handling' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/rake-0.9.2/lib/rake/application.rb:59:in `run' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/rake-0.9.2/bin/rake:32:in `<top (required)>' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/bin/rake:19:in `load' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/bin/rake:19:in `<main>' 
Tasks: TOP => db:migrate => environment 

user.rbは次のようになりますdevise :database_authenticatable...行を実行してrake db:migrate --stackを実行すると、このエラーが発生します。

WARNING: Global access to Rake DSL methods is deprecated. Please include 
    ... Rake::DSL into classes and modules which use the Rake DSL methods. 
WARNING: DSL method Elephant::Application#task called at /Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/railties-3.0.1/lib/rails/application.rb:214:in `initialize_tasks' 
** Invoke db:migrate (first_time) 
** Invoke environment (first_time) 
** Execute environment 
rake aborted! 
User does not respond to 'devise' method. This usually means you haven't loaded your ORM file or it's being loaded too late. To fix it, be sure to require 'devise/orm/YOUR_ORM' inside 'config/initializers/devise.rb' or before your application definition in 'config/application.rb' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/devise-1.1.5/lib/devise/rails/routes.rb:245:in `raise_no_devise_method_error!' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/devise-1.1.5/lib/devise/rails/routes.rb:140:in `block in devise_for' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/devise-1.1.5/lib/devise/rails/routes.rb:136:in `each' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/devise-1.1.5/lib/devise/rails/routes.rb:136:in `devise_for' 
/Users/ben/rails_projects/elephant/config/routes.rb:4:in `block in <top (required)>' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/actionpack-3.0.1/lib/action_dispatch/routing/route_set.rb:233:in `instance_exec' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/actionpack-3.0.1/lib/action_dispatch/routing/route_set.rb:233:in `draw' 
/Users/ben/rails_projects/elephant/config/routes.rb:1:in `<top (required)>' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/activesupport-3.0.1/lib/active_support/dependencies.rb:235:in `load' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/activesupport-3.0.1/lib/active_support/dependencies.rb:235:in `block in load' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/activesupport-3.0.1/lib/active_support/dependencies.rb:225:in `block in load_dependency' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/activesupport-3.0.1/lib/active_support/dependencies.rb:591:in `new_constants_in' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/activesupport-3.0.1/lib/active_support/dependencies.rb:225:in `load_dependency' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/activesupport-3.0.1/lib/active_support/dependencies.rb:235:in `load' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/railties-3.0.1/lib/rails/application.rb:127:in `block in reload_routes!' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/railties-3.0.1/lib/rails/application.rb:127:in `each' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/railties-3.0.1/lib/rails/application.rb:127:in `reload_routes!' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/railties-3.0.1/lib/rails/application.rb:120:in `block in routes_reloader' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/activesupport-3.0.1/lib/active_support/file_update_checker.rb:32:in `call' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/activesupport-3.0.1/lib/active_support/file_update_checker.rb:32:in `execute_if_updated' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/actionpack-3.0.1/lib/action_dispatch/railtie.rb:14:in `block (2 levels) in <class:Railtie>' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/activesupport-3.0.1/lib/active_support/callbacks.rb:419:in `_run_prepare_callbacks' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/actionpack-3.0.1/lib/action_dispatch/middleware/callbacks.rb:40:in `initialize' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/actionpack-3.0.1/lib/action_dispatch/middleware/stack.rb:33:in `new' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/actionpack-3.0.1/lib/action_dispatch/middleware/stack.rb:33:in `build' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/actionpack-3.0.1/lib/action_dispatch/middleware/stack.rb:79:in `block in build' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/actionpack-3.0.1/lib/action_dispatch/middleware/stack.rb:79:in `each' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/actionpack-3.0.1/lib/action_dispatch/middleware/stack.rb:79:in `inject' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/actionpack-3.0.1/lib/action_dispatch/middleware/stack.rb:79:in `build' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/railties-3.0.1/lib/rails/application.rb:162:in `app' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/railties-3.0.1/lib/rails/application/finisher.rb:35:in `block in <module:Finisher>' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/railties-3.0.1/lib/rails/initializable.rb:25:in `instance_exec' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/railties-3.0.1/lib/rails/initializable.rb:25:in `run' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/railties-3.0.1/lib/rails/initializable.rb:50:in `block in run_initializers' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/railties-3.0.1/lib/rails/initializable.rb:49:in `each' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/railties-3.0.1/lib/rails/initializable.rb:49:in `run_initializers' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/railties-3.0.1/lib/rails/application.rb:134:in `initialize!' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/railties-3.0.1/lib/rails/application.rb:77:in `method_missing' 
/Users/ben/rails_projects/elephant/config/environment.rb:5:in `<top (required)>' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/activesupport-3.0.1/lib/active_support/dependencies.rb:239:in `require' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/activesupport-3.0.1/lib/active_support/dependencies.rb:239:in `block in require' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/activesupport-3.0.1/lib/active_support/dependencies.rb:225:in `block in load_dependency' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/activesupport-3.0.1/lib/active_support/dependencies.rb:591:in `new_constants_in' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/activesupport-3.0.1/lib/active_support/dependencies.rb:225:in `load_dependency' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/activesupport-3.0.1/lib/active_support/dependencies.rb:239:in `require' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/railties-3.0.1/lib/rails/application.rb:103:in `require_environment!' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/railties-3.0.1/lib/rails/application.rb:216:in `block in initialize_tasks' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/rake-0.9.2/lib/rake/task.rb:205:in `call' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/rake-0.9.2/lib/rake/task.rb:205:in `block in execute' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/rake-0.9.2/lib/rake/task.rb:200:in `each' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/rake-0.9.2/lib/rake/task.rb:200:in `execute' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/rake-0.9.2/lib/rake/task.rb:158:in `block in invoke_with_call_chain' 
/Users/ben/.rvm/rubies/ruby-1.9.2-p0/lib/ruby/1.9.1/monitor.rb:201:in `mon_synchronize' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/rake-0.9.2/lib/rake/task.rb:151:in `invoke_with_call_chain' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/rake-0.9.2/lib/rake/task.rb:176:in `block in invoke_prerequisites' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/rake-0.9.2/lib/rake/task.rb:174:in `each' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/rake-0.9.2/lib/rake/task.rb:174:in `invoke_prerequisites' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/rake-0.9.2/lib/rake/task.rb:157:in `block in invoke_with_call_chain' 
/Users/ben/.rvm/rubies/ruby-1.9.2-p0/lib/ruby/1.9.1/monitor.rb:201:in `mon_synchronize' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/rake-0.9.2/lib/rake/task.rb:151:in `invoke_with_call_chain' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/rake-0.9.2/lib/rake/task.rb:144:in `invoke' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/rake-0.9.2/lib/rake/application.rb:112:in `invoke_task' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/rake-0.9.2/lib/rake/application.rb:90:in `block (2 levels) in top_level' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/rake-0.9.2/lib/rake/application.rb:90:in `each' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/rake-0.9.2/lib/rake/application.rb:90:in `block in top_level' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/rake-0.9.2/lib/rake/application.rb:129:in `standard_exception_handling' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/rake-0.9.2/lib/rake/application.rb:84:in `top_level' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/rake-0.9.2/lib/rake/application.rb:62:in `block in run' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/rake-0.9.2/lib/rake/application.rb:129:in `standard_exception_handling' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/rake-0.9.2/lib/rake/application.rb:59:in `run' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/gems/rake-0.9.2/bin/rake:32:in `<top (required)>' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/bin/rake:19:in `load' 
/Users/ben/.rvm/gems/ruby-1.9.2-p0/bin/rake:19:in `<main>' 
Tasks: TOP => db:migrate => environment 

これらのエラーの原因を教えてください。 uはルビー1.8.7 &熊手0.9〜を使用してい

私はRailsの3.0.1と

Answer 1

のRuby 1.9.2を実行しているのですか？

module ::YOUR_APP_NAME 
    class Application 
     include Rake::DSL 
    end 
end