我正在尝试在 rails 4 中使用“rails generate devise model1”，但出现以下错误。
> /home/p4/.rvm/gems/ruby-2.0.0-p247/gems/actionpack-4.0.0/lib/action_dispatch/routing/mapper.rb:229:in `default_controller_and_action': missing :controller (ArgumentError)
from /home/p4/.rvm/gems/ruby-2.0.0-p247/gems/actionpack-4.0.0/lib/action_dispatch/routing/mapper.rb:116:in `normalize_options!'
from /home/p4/.rvm/gems/ruby-2.0.0-p247/gems/actionpack-4.0.0/lib/action_dispatch/routing/mapper.rb:64:in `initialize'
from /home/p4/.rvm/gems/ruby-2.0.0-p247/gems/actionpack-4.0.0/lib/action_dispatch/routing/mapper.rb:1438:in `new'
from /home/p4/.rvm/gems/ruby-2.0.0-p247/gems/actionpack-4.0.0/lib/action_dispatch/routing/mapper.rb:1438:in `add_route'
from /home/p4/.rvm/gems/ruby-2.0.0-p247/gems/actionpack-4.0.0/lib/action_dispatch/routing/mapper.rb:1417:in `decomposed_match'
from /home/p4/.rvm/gems/ruby-2.0.0-p247/gems/actionpack-4.0.0/lib/action_dispatch/routing/mapper.rb:1398:in `block in match'
from /home/p4/.rvm/gems/ruby-2.0.0-p247/gems/actionpack-4.0.0/lib/action_dispatch/routing/mapper.rb:1389:in `each'
from /home/p4/.rvm/gems/ruby-2.0.0-p247/gems/actionpack-4.0.0/lib/action_dispatch/routing/mapper.rb:1389:in `match'
from /home/p4/.rvm/gems/ruby-2.0.0-p247/gems/actionpack-4.0.0/lib/action_dispatch/routing/mapper.rb:330:in `root'
from /home/p4/.rvm/gems/ruby-2.0.0-p247/gems/actionpack-4.0.0/lib/action_dispatch/routing/mapper.rb:1459:in `root'
from /home/p4/rails_tut/test_app/config/routes.rb:3:in `block in <top (required)>'
from /home/p4/.rvm/gems/ruby-2.0.0-p247/gems/actionpack-4.0.0/lib/action_dispatch/routing/route_set.rb:316:in `instance_exec'
from /home/p4/.rvm/gems/ruby-2.0.0-p247/gems/actionpack-4.0.0/lib/action_dispatch/routing/route_set.rb:316:in `eval_block'
from /home/p4/.rvm/gems/ruby-2.0.0-p247/gems/actionpack-4.0.0/lib/action_dispatch/routing/route_set.rb:294:in `draw'
from /home/p4/rails_tut/test_app/config/routes.rb:1:in `<top (required)>'
from /home/p4/.rvm/gems/ruby-2.0.0-p247/gems/activesupport-4.0.0/lib/active_support/dependencies.rb:222:in `load'
from /home/p4/.rvm/gems/ruby-2.0.0-p247/gems/activesupport-4.0.0/lib/active_support/dependencies.rb:222:in `block in load'
from /home/p4/.rvm/gems/ruby-2.0.0-p247/gems/activesupport-4.0.0/lib/active_support/dependencies.rb:213:in `load_dependency'
from /home/p4/.rvm/gems/ruby-2.0.0-p247/gems/activesupport-4.0.0/lib/active_support/dependencies.rb:222:in `load'
from /home/p4/.rvm/gems/ruby-2.0.0-p247/gems/railties-4.0.0/lib/rails/application/routes_reloader.rb:40:in `block in load_paths'
from /home/p4/.rvm/gems/ruby-2.0.0-p247/gems/railties-4.0.0/lib/rails/application/routes_reloader.rb:40:in `each'
from /home/p4/.rvm/gems/ruby-2.0.0-p247/gems/railties-4.0.0/lib/rails/application/routes_reloader.rb:40:in `load_paths'
from /home/p4/.rvm/gems/ruby-2.0.0-p247/gems/railties-4.0.0/lib/rails/application/routes_reloader.rb:16:in `reload!'
from /home/p4/.rvm/gems/ruby-2.0.0-p247/gems/railties-4.0.0/lib/rails/application/routes_reloader.rb:26:in `block in updater'
from /home/p4/.rvm/gems/ruby-2.0.0-p247/gems/activesupport-4.0.0/lib/active_support/file_update_checker.rb:75:in `call'
from /home/p4/.rvm/gems/ruby-2.0.0-p247/gems/activesupport-4.0.0/lib/active_support/file_update_checker.rb:75:in `execute'
from /home/p4/.rvm/gems/ruby-2.0.0-p247/gems/railties-4.0.0/lib/rails/application/routes_reloader.rb:27:in `updater'
from /home/p4/.rvm/gems/ruby-2.0.0-p247/gems/railties-4.0.0/lib/rails/application/routes_reloader.rb:6:in `execute_if_updated'
from /home/p4/.rvm/gems/ruby-2.0.0-p247/gems/railties-4.0.0/lib/rails/application/finisher.rb:69:in `block in <module:Finisher>'
from /home/p4/.rvm/gems/ruby-2.0.0-p247/gems/railties-4.0.0/lib/rails/initializable.rb:30:in `instance_exec'
from /home/p4/.rvm/gems/ruby-2.0.0-p247/gems/railties-4.0.0/lib/rails/initializable.rb:30:in `run'
from /home/p4/.rvm/gems/ruby-2.0.0-p247/gems/railties-4.0.0/lib/rails/initializable.rb:55:in `block in run_initializers'
from /home/p4/.rvm/rubies/ruby-2.0.0-p247/lib/ruby/2.0.0/tsort.rb:150:in `block in tsort_each'
from /home/p4/.rvm/rubies/ruby-2.0.0-p247/lib/ruby/2.0.0/tsort.rb:183:in `block (2 levels) in each_strongly_connected_component'
from /home/p4/.rvm/rubies/ruby-2.0.0-p247/lib/ruby/2.0.0/tsort.rb:219:in `each_strongly_connected_component_from'
from /home/p4/.rvm/rubies/ruby-2.0.0-p247/lib/ruby/2.0.0/tsort.rb:182:in `block in each_strongly_connected_component'
from /home/p4/.rvm/rubies/ruby-2.0.0-p247/lib/ruby/2.0.0/tsort.rb:180:in `each'
from /home/p4/.rvm/rubies/ruby-2.0.0-p247/lib/ruby/2.0.0/tsort.rb:180:in `each_strongly_connected_component'
from /home/p4/.rvm/rubies/ruby-2.0.0-p247/lib/ruby/2.0.0/tsort.rb:148:in `tsort_each'
from /home/p4/.rvm/gems/ruby-2.0.0-p247/gems/railties-4.0.0/lib/rails/initializable.rb:54:in `run_initializers'
from /home/p4/.rvm/gems/ruby-2.0.0-p247/gems/railties-4.0.0/lib/rails/application.rb:215:in `initialize!'
from /home/p4/.rvm/gems/ruby-2.0.0-p247/gems/railties-4.0.0/lib/rails/railtie/configurable.rb:30:in `method_missing'
from /home/p4/rails_tut/test_app/config/environment.rb:5:in `<top (required)>'
from /home/p4/.rvm/gems/ruby-2.0.0-p247/gems/activesupport-4.0.0/lib/active_support/dependencies.rb:228:in `require'
from /home/p4/.rvm/gems/ruby-2.0.0-p247/gems/activesupport-4.0.0/lib/active_support/dependencies.rb:228:in `block in require'
from /home/p4/.rvm/gems/ruby-2.0.0-p247/gems/activesupport-4.0.0/lib/active_support/dependencies.rb:213:in `load_dependency'
from /home/p4/.rvm/gems/ruby-2.0.0-p247/gems/activesupport-4.0.0/lib/active_support/dependencies.rb:228:in `require'
from /home/p4/.rvm/gems/ruby-2.0.0-p247/gems/railties-4.0.0/lib/rails/application.rb:189:in `require_environment!'
from /home/p4/.rvm/gems/ruby-2.0.0-p247/gems/railties-4.0.0/lib/rails/commands.rb:45:in `<top (required)>'
from bin/rails:4:in `require'
from bin/rails:4:in `<main>'
我不知道rails的内部工作是什么，因为这个错误似乎是来自'mapping.rb'的一些问题。
以下是我的 routes.rb
TestApp::Application.routes.draw do
root 'dunbs' => 'dunbs#index'
end