Why is my development server not loading? default_controller_and_action': missing :action (ArgumentError)

Question

I'm a Ruby nuby (and new to Stack Overflow) working on the Rails Tutorial by Michael Hartl and all of a sudden my development server won't load and keeps exiting. Console also won't load and Rspec spec/ produces errors/exceptions. I am including some output from the terminal, your help is much appreciated.

Exiting
/Users/ameedachowdhury/.rvm/gems/ruby-1.9.2-p0@rails3tutorial/gems/actionpack-3.0.3/lib/action_dispatch/routing/mapper.rb:164:in `default_controller_and_action': missing :action (ArgumentError)
    from /Users/ameedachowdhury/.rvm/gems/ruby-1.9.2-p0@rails3tutorial/gems/actionpack-3.0.3/lib/action_dispatch/routing/mapper.rb:68:in `normalize_options!'
    from /Users/ameedachowdhury/.rvm/gems/ruby-1.9.2-p0@rails3tutorial/gems/actionpack-3.0.3/lib/action_dispatch/routing/mapper.rb:51:in `initialize'
    from /Users/ameedachowdhury/.rvm/gems/ruby-1.9.2-p0@rails3tutorial/gems/actionpack-3.0.3/lib/action_dispatch/routing/mapper.rb:261:in `new'
    from /Users/ameedachowdhury/.rvm/gems/ruby-1.9.2-p0@rails3tutorial/gems/actionpack-3.0.3/lib/action_dispatch/routing/mapper.rb:261:in `match'
    from /Users/ameedachowdhury/.rvm/gems/ruby-1.9.2-p0@rails3tutorial/gems/actionpack-3.0.3/lib/action_dispatch/routing/mapper.rb:1112:in `match'
    from /Users/ameedachowdhury/.rvm/gems/ruby-1.9.2-p0@rails3tutorial/gems/actionpack-3.0.3/lib/action_dispatch/routing/mapper.rb:1297:in `match'
    from /Users/ameedachowdhury/rails_projects/railstutorial/config/routes.rb:11:in `block in <top (required)>'
    from /Users/ameedachowdhury/.rvm/gems/ruby-1.9.2-p0@rails3tutorial/gems/actionpack-3.0.3/lib/action_dispatch/routing/route_set.rb:233:in `instance_exec'
    from /Users/ameedachowdhury/.rvm/gems/ruby-1.9.2-p0@rails3tutorial/gems/actionpack-3.0.3/lib/action_dispatch/routing/route_set.rb:233:in `draw'
    from /Users/ameedachowdhury/rails_projects/railstutorial/config/routes.rb:1:in `<top (required)>'
    from /Users/ameedachowdhury/.rvm/gems/ruby-1.9.2-p0@rails3tutorial/gems/activesupport-3.0.3/lib/active_support/dependencies.rb:235:in `load'
    from /Users/ameedachowdhury/.rvm/gems/ruby-1.9.2-p0@rails3tutorial/gems/activesupport-3.0.3/lib/active_support/dependencies.rb:235:in `block in load'
    from /Users/ameedachowdhury/.rvm/gems/ruby-1.9.2-p0@rails3tutorial/gems/activesupport-3.0.3/lib/active_support/dependencies.rb:225:in `block in load_dependency'
    from /Users/ameedachowdhury/.rvm/gems/ruby-1.9.2-p0@rails3tutorial/gems/activesupport-3.0.3/lib/active_support/dependencies.rb:596:in `new_constants_in'
    from /Users/ameedachowdhury/.rvm/gems/ruby-1.9.2-p0@rails3tutorial/gems/activesupport-3.0.3/lib/active_support/dependencies.rb:225:in `load_dependency'
    from /Users/ameedachowdhury/.rvm/gems/ruby-1.9.2-p0@rails3tutorial/gems/activesupport-3.0.3/lib/active_support/dependencies.rb:235:in `load'
    from /Users/ameedachowdhury/.rvm/gems/ruby-1.9.2-p0@rails3tutorial/gems/railties-3.0.3/lib/rails/application.rb:127:in `block in reload_routes!'
    from /Users/ameedachowdhury/.rvm/gems/ruby-1.9.2-p0@rails3tutorial/gems/railties-3.0.3/lib/rails/application.rb:127:in `each'
    from /Users/ameedachowdhury/.rvm/gems/ruby-1.9.2-p0@rails3tutorial/gems/railties-3.0.3/lib/rails/application.rb:127:in `reload_routes!'
    from /Users/ameedachowdhury/.rvm/gems/ruby-1.9.2-p0@rails3tutorial/gems/railties-3.0.3/lib/rails/application.rb:120:in `block in routes_reloader'
    from /Users/ameedachowdhury/.rvm/gems/ruby-1.9.2-p0@rails3tutorial/gems/activesupport-3.0.3/lib/active_support/file_update_checker.rb:32:in `call'
    from /Users/ameedachowdhury/.rvm/gems/ruby-1.9.2-p0@rails3tutorial/gems/activesupport-3.0.3/lib/active_support/file_update_checker.rb:32:in `execute_if_updated'
    from /Users/ameedachowdhury/.rvm/gems/ruby-1.9.2-p0@rails3tutorial/gems/railties-3.0.3/lib/rails/application/finisher.rb:51:in `block (2 levels) in <module:Finisher>'
    from /Users/ameedachowdhury/.rvm/gems/ruby-1.9.2-p0@rails3tutorial/gems/railties-3.0.3/lib/rails/application/finisher.rb:52:in `call'
    from /Users/ameedachowdhury/.rvm/gems/ruby-1.9.2-p0@rails3tutorial/gems/railties-3.0.3/lib/rails/application/finisher.rb:52:in `block in <module:Finisher>'
    from /Users/ameedachowdhury/.rvm/gems/ruby-1.9.2-p0@rails3tutorial/gems/railties-3.0.3/lib/rails/initializable.rb:25:in `instance_exec'
    from /Users/ameedachowdhury/.rvm/gems/ruby-1.9.2-p0@rails3tutorial/gems/railties-3.0.3/lib/rails/initializable.rb:25:in `run'
    from /Users/ameedachowdhury/.rvm/gems/ruby-1.9.2-p0@rails3tutorial/gems/railties-3.0.3/lib/rails/initializable.rb:50:in `block in run_initializers'
    from /Users/ameedachowdhury/.rvm/gems/ruby-1.9.2-p0@rails3tutorial/gems/railties-3.0.3/lib/rails/initializable.rb:49:in `each'
    from /Users/ameedachowdhury/.rvm/gems/ruby-1.9.2-p0@rails3tutorial/gems/railties-3.0.3/lib/rails/initializable.rb:49:in `run_initializers'
    from /Users/ameedachowdhury/.rvm/gems/ruby-1.9.2-p0@rails3tutorial/gems/railties-3.0.3/lib/rails/application.rb:134:in `initialize!'
    from /Users/ameedachowdhury/.rvm/gems/ruby-1.9.2-p0@rails3tutorial/gems/railties-3.0.3/lib/rails/application.rb:77:in `method_missing'
    from /Users/ameedachowdhury/rails_projects/railstutorial/config/environment.rb:5:in `<top (required)>'
    from /Users/ameedachowdhury/rails_projects/railstutorial/config.ru:3:in `require'
    from /Users/ameedachowdhury/rails_projects/railstutorial/config.ru:3:in `block in <main>'
    from /Users/ameedachowdhury/.rvm/gems/ruby-1.9.2-p0@rails3tutorial/gems/rack-1.2.1/lib/rack/builder.rb:46:in `instance_eval'
    from /Users/ameedachowdhury/.rvm/gems/ruby-1.9.2-p0@rails3tutorial/gems/rack-1.2.1/lib/rack/builder.rb:46:in `initialize'
    from /Users/ameedachowdhury/rails_projects/railstutorial/config.ru:1:in `new'
    from /Users/ameedachowdhury/rails_projects/railstutorial/config.ru:1:in `<main>'
    from /Users/ameedachowdhury/.rvm/gems/ruby-1.9.2-p0@rails3tutorial/gems/rack-1.2.1/lib/rack/builder.rb:35:in `eval'
    from /Users/ameedachowdhury/.rvm/gems/ruby-1.9.2-p0@rails3tutorial/gems/rack-1.2.1/lib/rack/builder.rb:35:in `parse_file'
    from /Users/ameedachowdhury/.rvm/gems/ruby-1.9.2-p0@rails3tutorial/gems/rack-1.2.1/lib/rack/server.rb:162:in `app'
    from /Users/ameedachowdhury/.rvm/gems/ruby-1.9.2-p0@rails3tutorial/gems/rack-1.2.1/lib/rack/server.rb:248:in `wrapped_app'
    from /Users/ameedachowdhury/.rvm/gems/ruby-1.9.2-p0@rails3tutorial/gems/rack-1.2.1/lib/rack/server.rb:213:in `start'
    from /Users/ameedachowdhury/.rvm/gems/ruby-1.9.2-p0@rails3tutorial/gems/railties-3.0.3/lib/rails/commands/server.rb:65:in `start'
    from /Users/ameedachowdhury/.rvm/gems/ruby-1.9.2-p0@rails3tutorial/gems/railties-3.0.3/lib/rails/commands.rb:30:in `block in <top (required)>'
    from /Users/ameedachowdhury/.rvm/gems/ruby-1.9.2-p0@rails3tutorial/gems/railties-3.0.3/lib/rails/commands.rb:27:in `tap'
    from /Users/ameedachowdhury/.rvm/gems/ruby-1.9.2-p0@rails3tutorial/gems/railties-3.0.3/lib/rails/commands.rb:27:in `<top (required)>'
    from script/rails:6:in `require'
    from script/rails:6:in `<main>'
ameeda-chowdhurys-macbook:railstutorial ameedachowdhury$ 

---

Solution 1

When I ran into this problem, it was because one of the routes in routes.rb had a slash (/) instead of the hash (#) when using the controller#action syntax (I used "controller/action", which was incorrect).

For example, I accidentally had root :to => 'home/index'. It was supposed to be root :to => 'home#index'.

I found this solution in here.

Solution 2

This is caused by incorrect routes -
Please check your config/routes.rb , even if one route mentioned is wrong then this error is thrown !!
Also make sure that the route is

'/url/for/something' => 'controller#action'

or

root :to => 'controller#action

Solution 3

I'm also a Ruby nuby and had the same error while working on the Rails Tutorial by Michael Hartl. If you're like me, you might be just typing in all code that appears in the book with really reading or understanding the text. Not everything is step by step. In demonstrating camel case vs. snake case Hartl shows a box with the following code

$ rails generate controller static_pages ...

Here, Hartl is simply trying to contrast instructions to generate a StaticPages controller using snake case, rather than camel case, which was done in Listing 3.4. The dots "..." are simply to edit out or truncate the rest of the instructions for the cmd line. I typed in exactly what was shown and wound up with the following in my routes file:

SampleApp::Application.routes.draw do
 get "static_pages/..."

 get "static_pages/home"

 get "static_pages/help"

open up your routes file, delete

get "static_pages/..."

save the routes file, and try starting rails server again.

I also destroyed "rails generate controller static_pages ..." Not sure if that had any effect, but now everything works.

Solution 4

By default you get this:

Rails.application.routes.draw do
  get 'static_pages/...'

  get 'static_pages/home'

  get 'static_pages/help'

JUST ERASE THIS:

  get 'static_pages/...'

AND YOU WILL HAVE THIS IN THE ROUTES.RB FILE

Rails.application.routes.draw do

  get 'static_pages/home'

  get 'static_pages/help'

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