Rails 4 での認証に最適な gem はどれですか?? devise を使用しようとしましたが、問題が発生しました。
.rvm/gems/ruby-2.0.0-p0/gems/activemodel-4.0.0.beta1/lib/active_model/deprecated_mass_assignment_security.rb:14:in `attr_accessible': `attr_accessible` is extracted out of Rails into a gem. Please use new recommended protection model for params(strong_parameters) or add `protected_attributes` to your Gemfile to use old one. (RuntimeError)
from /home/leapfrog/projects/kathloc/app/models/user.rb:8:in `<class:User>'
from /home/leapfrog/projects/kathloc/app/models/user.rb:1:in `<top (required)>'
from /home/leapfrog/.rvm/gems/ruby-2.0.0-p0/gems/activesupport-4.0.0.beta1/lib/active_support/dependencies.rb:423:in `load'
from /home/leapfrog/.rvm/gems/ruby-2.0.0-p0/gems/activesupport-4.0.0.beta1/lib/active_support/dependencies.rb:423:in `block in load_file'
from /home/leapfrog/.rvm/gems/ruby-2.0.0-p0/gems/activesupport-4.0.0.beta1/lib/active_support/dependencies.rb:615:in `new_constants_in'
from /home/leapfrog/.rvm/gems/ruby-2.0.0-p0/gems/activesupport-4.0.0.beta1/lib/active_support/dependencies.rb:422:in `load_file'
from /home/leapfrog/.rvm/gems/ruby-2.0.0-p0/gems/activesupport-4.0.0.beta1/lib/active_support/dependencies.rb:323:in `require_or_load'
from /home/leapfrog/.rvm/gems/ruby-2.0.0-p0/gems/activesupport-4.0.0.beta1/lib/active_support/dependencies.rb:462:in `load_missing_constant'
from /home/leapfrog/.rvm/gems/ruby-2.0.0-p0/gems/activesupport-4.0.0.beta1/lib/active_support/dependencies.rb:183:in `const_missing'
from /home/leapfrog/.rvm/gems/ruby-2.0.0-p0/gems/activesupport-4.0.0.beta1/lib/active_support/inflector/methods.rb:226:in `const_get'
from /home/leapfrog/.rvm/gems/ruby-2.0.0-p0/gems/activesupport-4.0.0.beta1/lib/active_support/inflector/methods.rb:226:in `block in constantize'
from /home/leapfrog/.rvm/gems/ruby-2.0.0-p0/gems/activesupport-4.0.0.beta1/lib/active_support/inflector/methods.rb:224:in `each'
from /home/leapfrog/.rvm/gems/ruby-2.0.0-p0/gems/activesupport-4.0.0.beta1/lib/active_support/inflector/methods.rb:224:in `inject'
from /home/leapfrog/.rvm/gems/ruby-2.0.0-p0/gems/activesupport-4.0.0.beta1/lib/active_support/inflector/methods.rb:224:in `constantize'
from /home/leapfrog/.rvm/gems/ruby-2.0.0-p0/gems/activesupport-4.0.0.beta1/lib/active_support/dependencies.rb:534:in `get'
from /home/leapfrog/.rvm/gems/ruby-2.0.0-p0/gems/activesupport-4.0.0.beta1/lib/active_support/dependencies.rb:565:in `constantize'
from /home/leapfrog/.rvm/gems/ruby-2.0.0-p0/gems/devise-1.5.4/lib/devise.rb:261:in `get'
from /home/leapfrog/.rvm/gems/ruby-2.0.0-p0/gems/devise-1.5.4/lib/devise/mapping.rb:77:in `to'
from /home/leapfrog/.rvm/gems/ruby-2.0.0-p0/gems/devise-1.5.4/lib/devise/mapping.rb:72:in `modules'
from /home/leapfrog/.rvm/gems/ruby-2.0.0-p0/gems/devise-1.5.4/lib/devise/mapping.rb:89:in `routes'
from /home/leapfrog/.rvm/gems/ruby-2.0.0-p0/gems/devise-1.5.4/lib/devise/mapping.rb:156:in `default_used_route'
from /home/leapfrog/.rvm/gems/ruby-2.0.0-p0/gems/devise-1.5.4/lib/devise/mapping.rb:66:in `initialize'
from /home/leapfrog/.rvm/gems/ruby-2.0.0-p0/gems/devise-1.5.4/lib/devise.rb:291:in `new'
from /home/leapfrog/.rvm/gems/ruby-2.0.0-p0/gems/devise-1.5.4/lib/devise.rb:291:in `add_mapping'
from /home/leapfrog/.rvm/gems/ruby-2.0.0-p0/gems/devise-1.5.4/lib/devise/rails/routes.rb:193:in `block in devise_for'
from /home/leapfrog/.rvm/gems/ruby-2.0.0-p0/gems/devise-1.5.4/lib/devise/rails/routes.rb:192:in `each'
from /home/leapfrog/.rvm/gems/ruby-2.0.0-p0/gems/devise-1.5.4/lib/devise/rails/routes.rb:192:in `devise_for'
from /home/leapfrog/projects/kathloc/config/routes.rb:2:in `block in <top (required)>'
from /home/leapfrog/.rvm/gems/ruby-2.0.0-p0/gems/actionpack-4.0.0.beta1/lib/action_dispatch/routing/route_set.rb:320:in `instance_exec'
from /home/leapfrog/.rvm/gems/ruby-2.0.0-p0/gems/actionpack-4.0.0.beta1/lib/action_dispatch/routing/route_set.rb:320:in `eval_block'
from /home/leapfrog/.rvm/gems/ruby-2.0.0-p0/gems/actionpack-4.0.0.beta1/lib/action_dispatch/routing/route_set.rb:298:in `draw'
from /home/leapfrog/projects/kathloc/config/routes.rb:1:in `<top (required)>'
from /home/leapfrog/.rvm/gems/ruby-2.0.0-p0/gems/activesupport-4.0.0.beta1/lib/active_support/dependencies.rb:222:in `load'
from /home/leapfrog/.rvm/gems/ruby-2.0.0-p0/gems/activesupport-4.0.0.beta1/lib/active_support/dependencies.rb:222:in `block in load'
from /home/leapfrog/.rvm/gems/ruby-2.0.0-p0/gems/activesupport-4.0.0.beta1/lib/active_support/dependencies.rb:213:in `load_dependency'
from /home/leapfrog/.rvm/gems/ruby-2.0.0-p0/gems/activesupport-4.0.0.beta1/lib/active_support/dependencies.rb:222:in `load'
from /home/leapfrog/.rvm/gems/ruby-2.0.0-p0/gems/railties-4.0.0.beta1/lib/rails/application/routes_reloader.rb:40:in `block in load_paths'
from /home/leapfrog/.rvm/gems/ruby-2.0.0-p0/gems/railties-4.0.0.beta1/lib/rails/application/routes_reloader.rb:40:in `each'
from /home/leapfrog/.rvm/gems/ruby-2.0.0-p0/gems/railties-4.0.0.beta1/lib/rails/application/routes_reloader.rb:40:in `load_paths'
from /home/leapfrog/.rvm/gems/ruby-2.0.0-p0/gems/railties-4.0.0.beta1/lib/rails/application/routes_reloader.rb:16:in `reload!'
from /home/leapfrog/.rvm/gems/ruby-2.0.0-p0/gems/railties-4.0.0.beta1/lib/rails/application/routes_reloader.rb:26:in `block in updater'
from /home/leapfrog/.rvm/gems/ruby-2.0.0-p0/gems/activesupport-4.0.0.beta1/lib/active_support/file_update_checker.rb:75:in `call'
from /home/leapfrog/.rvm/gems/ruby-2.0.0-p0/gems/activesupport-4.0.0.beta1/lib/active_support/file_update_checker.rb:75:in `execute'
from /home/leapfrog/.rvm/gems/ruby-2.0.0-p0/gems/railties-4.0.0.beta1/lib/rails/application/routes_reloader.rb:27:in `updater'
from /home/leapfrog/.rvm/gems/ruby-2.0.0-p0/gems/railties-4.0.0.beta1/lib/rails/application/routes_reloader.rb:7:in `execute_if_updated'
from /home/leapfrog/.rvm/gems/ruby-2.0.0-p0/gems/railties-4.0.0.beta1/lib/rails/application/finisher.rb:69:in `block in <module:Finisher>'
from /home/leapfrog/.rvm/gems/ruby-2.0.0-p0/gems/railties-4.0.0.beta1/lib/rails/initializable.rb:30:in `instance_exec'
from /home/leapfrog/.rvm/gems/ruby-2.0.0-p0/gems/railties-4.0.0.beta1/lib/rails/initializable.rb:30:in `run'
from /home/leapfrog/.rvm/gems/ruby-2.0.0-p0/gems/railties-4.0.0.beta1/lib/rails/initializable.rb:55:in `block in run_initializers'
from /home/leapfrog/.rvm/rubies/ruby-2.0.0-p0/lib/ruby/2.0.0/tsort.rb:150:in `block in tsort_each'
from /home/leapfrog/.rvm/rubies/ruby-2.0.0-p0/lib/ruby/2.0.0/tsort.rb:183:in `block (2 levels) in each_strongly_connected_component'
from /home/leapfrog/.rvm/rubies/ruby-2.0.0-p0/lib/ruby/2.0.0/tsort.rb:219:in `each_strongly_connected_component_from'
from /home/leapfrog/.rvm/rubies/ruby-2.0.0-p0/lib/ruby/2.0.0/tsort.rb:182:in `block in each_strongly_connected_component'
from /home/leapfrog/.rvm/rubies/ruby-2.0.0-p0/lib/ruby/2.0.0/tsort.rb:180:in `each'
from /home/leapfrog/.rvm/rubies/ruby-2.0.0-p0/lib/ruby/2.0.0/tsort.rb:180:in `each_strongly_connected_component'
from /home/leapfrog/.rvm/rubies/ruby-2.0.0-p0/lib/ruby/2.0.0/tsort.rb:148:in `tsort_each'
from /home/leapfrog/.rvm/gems/ruby-2.0.0-p0/gems/railties-4.0.0.beta1/lib/rails/initializable.rb:54:in `run_initializers'
from /home/leapfrog/.rvm/gems/ruby-2.0.0-p0/gems/railties-4.0.0.beta1/lib/rails/application.rb:213:in `initialize!'
from /home/leapfrog/.rvm/gems/ruby-2.0.0-p0/gems/railties-4.0.0.beta1/lib/rails/railtie/configurable.rb:30:in `method_missing'
from /home/leapfrog/projects/kathloc/config/environment.rb:5:in `<top (required)>'
from /home/leapfrog/.rvm/gems/ruby-2.0.0-p0/gems/activesupport-4.0.0.beta1/lib/active_support/dependencies.rb:228:in `require'
from /home/leapfrog/.rvm/gems/ruby-2.0.0-p0/gems/activesupport-4.0.0.beta1/lib/active_support/dependencies.rb:228:in `block in require'
from /home/leapfrog/.rvm/gems/ruby-2.0.0-p0/gems/activesupport-4.0.0.beta1/lib/active_support/dependencies.rb:213:in `load_dependency'
from /home/leapfrog/.rvm/gems/ruby-2.0.0-p0/gems/activesupport-4.0.0.beta1/lib/active_support/dependencies.rb:228:in `require'
from /home/leapfrog/.rvm/gems/ruby-2.0.0-p0/gems/railties-4.0.0.beta1/lib/rails/application.rb:187:in `require_environment!'
from /home/leapfrog/.rvm/gems/ruby-2.0.0-p0/gems/railties-4.0.0.beta1/lib/rails/commands.rb:45:in `<top (required)>'
from bin/rails:4:in `require'
from bin/rails:4:in `<main>'