Uninitialized constant error message after a typo done while installing devise gem

Question

I just started learning how to program, but have been using Ubuntu for some years now, so I am well familiar with researching problems and errors, but either this area is too new for me, or I really cant find any specific answers for this.

I am taking a ruby on rails introduction course, and got to the point where I had to install the devise gem and here is where I made a mistake.

While following the instructions on the devise github page I accidentally typed in:

rails generate devise install

instead of

rails generate devise:install

Now, whenever I try to load

rails s

I get this error message:

/home/amer/.rvm/gems/ruby-1.9.3-p327/gems/activesupport-3.2.9/lib/active_support/inflector/methods.rb:230:in `block in constantize': uninitialized constant Install (NameError)
from /home/amer/.rvm/gems/ruby-1.9.3-p327/gems/activesupport-3.2.9/lib/active_support/inflector/methods.rb:229:in `each'
from /home/amer/.rvm/gems/ruby-1.9.3-p327/gems/activesupport-3.2.9/lib/active_support/inflector/methods.rb:229:in `constantize'
from /home/amer/.rvm/gems/ruby-1.9.3-p327/gems/devise-2.1.2/lib/devise.rb:256:in `get'
from /home/amer/.rvm/gems/ruby-1.9.3-p327/gems/devise-2.1.2/lib/devise/mapping.rb:77:in `to'
from /home/amer/.rvm/gems/ruby-1.9.3-p327/gems/devise-2.1.2/lib/devise/mapping.rb:72:in `modules'
from /home/amer/.rvm/gems/ruby-1.9.3-p327/gems/devise-2.1.2/lib/devise/mapping.rb:89:in `routes'
from /home/amer/.rvm/gems/ruby-1.9.3-p327/gems/devise-2.1.2/lib/devise/mapping.rb:156:in `default_used_route'
from /home/amer/.rvm/gems/ruby-1.9.3-p327/gems/devise-2.1.2/lib/devise/mapping.rb:66:in `initialize'
from /home/amer/.rvm/gems/ruby-1.9.3-p327/gems/devise-2.1.2/lib/devise.rb:290:in `new'
from /home/amer/.rvm/gems/ruby-1.9.3-p327/gems/devise-2.1.2/lib/devise.rb:290:in `add_mapping'
from /home/amer/.rvm/gems/ruby-1.9.3-p327/gems/devise-2.1.2/lib/devise/rails/routes.rb:208:in `block in devise_for'
from /home/amer/.rvm/gems/ruby-1.9.3-p327/gems/devise-2.1.2/lib/devise/rails/routes.rb:207:in `each'
from /home/amer/.rvm/gems/ruby-1.9.3-p327/gems/devise-2.1.2/lib/devise/rails/routes.rb:207:in `devise_for'
from /home/amer/Documents/Rails_Projects/omrails/omrails1/config/routes.rb:3:in `block in <top (required)>'
from /home/amer/.rvm/gems/ruby-1.9.3-p327/gems/actionpack-3.2.9/lib/action_dispatch/routing/route_set.rb:282:in `instance_exec'
from /home/amer/.rvm/gems/ruby-1.9.3-p327/gems/actionpack-3.2.9/lib/action_dispatch/routing/route_set.rb:282:in `eval_block'
from /home/amer/.rvm/gems/ruby-1.9.3-p327/gems/actionpack-3.2.9/lib/action_dispatch/routing/route_set.rb:260:in `draw'
from /home/amer/Documents/Rails_Projects/omrails/omrails1/config/routes.rb:1:in `<top (required)>'
from /home/amer/.rvm/gems/ruby-1.9.3-p327/gems/railties-3.2.9/lib/rails/application/routes_reloader.rb:40:in `block in load_paths'
from /home/amer/.rvm/gems/ruby-1.9.3-p327/gems/railties-3.2.9/lib/rails/application/routes_reloader.rb:40:in `each'
from /home/amer/.rvm/gems/ruby-1.9.3-p327/gems/railties-3.2.9/lib/rails/application/routes_reloader.rb:40:in `load_paths'
from /home/amer/.rvm/gems/ruby-1.9.3-p327/gems/railties-3.2.9/lib/rails/application/routes_reloader.rb:16:in `reload!'
from /home/amer/.rvm/gems/ruby-1.9.3-p327/gems/railties-3.2.9/lib/rails/application/routes_reloader.rb:26:in `block in updater'
from /home/amer/.rvm/gems/ruby-1.9.3-p327/gems/activesupport-3.2.9/lib/active_support/file_update_checker.rb:78:in `call'
from /home/amer/.rvm/gems/ruby-1.9.3-p327/gems/activesupport-3.2.9/lib/active_support/file_update_checker.rb:78:in `execute'
from /home/amer/.rvm/gems/ruby-1.9.3-p327/gems/railties-3.2.9/lib/rails/application/routes_reloader.rb:27:in `updater'
from /home/amer/.rvm/gems/ruby-1.9.3-p327/gems/railties-3.2.9/lib/rails/application/routes_reloader.rb:7:in `execute_if_updated'
from /home/amer/.rvm/gems/ruby-1.9.3-p327/gems/railties-3.2.9/lib/rails/application/finisher.rb:66:in `block in <module:Finisher>'
from /home/amer/.rvm/gems/ruby-1.9.3-p327/gems/railties-3.2.9/lib/rails/initializable.rb:30:in `instance_exec'
from /home/amer/.rvm/gems/ruby-1.9.3-p327/gems/railties-3.2.9/lib/rails/initializable.rb:30:in `run'
from /home/amer/.rvm/gems/ruby-1.9.3-p327/gems/railties-3.2.9/lib/rails/initializable.rb:55:in `block in run_initializers'
from /home/amer/.rvm/gems/ruby-1.9.3-p327/gems/railties-3.2.9/lib/rails/initializable.rb:54:in `each'
from /home/amer/.rvm/gems/ruby-1.9.3-p327/gems/railties-3.2.9/lib/rails/initializable.rb:54:in `run_initializers'
from /home/amer/.rvm/gems/ruby-1.9.3-p327/gems/railties-3.2.9/lib/rails/application.rb:136:in `initialize!'
from /home/amer/.rvm/gems/ruby-1.9.3-p327/gems/railties-3.2.9/lib/rails/railtie/configurable.rb:30:in `method_missing'
from /home/amer/Documents/Rails_Projects/omrails/omrails1/config/environment.rb:5:in `<top (required)>'
from /home/amer/Documents/Rails_Projects/omrails/omrails1/config.ru:4:in `block in <main>'
from /home/amer/.rvm/gems/ruby-1.9.3-p327/gems/rack-1.4.1/lib/rack/builder.rb:51:in `instance_eval'
from /home/amer/.rvm/gems/ruby-1.9.3-p327/gems/rack-1.4.1/lib/rack/builder.rb:51:in `initialize'
from /home/amer/Documents/Rails_Projects/omrails/omrails1/config.ru:1:in `new'
from /home/amer/Documents/Rails_Projects/omrails/omrails1/config.ru:1:in `<main>'
from /home/amer/.rvm/gems/ruby-1.9.3-p327/gems/rack-1.4.1/lib/rack/builder.rb:40:in `eval'
from /home/amer/.rvm/gems/ruby-1.9.3-p327/gems/rack-1.4.1/lib/rack/builder.rb:40:in `parse_file'
from /home/amer/.rvm/gems/ruby-1.9.3-p327/gems/rack-1.4.1/lib/rack/server.rb:200:in `app'
from /home/amer/.rvm/gems/ruby-1.9.3-p327/gems/railties-3.2.9/lib/rails/commands/server.rb:46:in `app'
from /home/amer/.rvm/gems/ruby-1.9.3-p327/gems/rack-1.4.1/lib/rack/server.rb:301:in `wrapped_app'
from /home/amer/.rvm/gems/ruby-1.9.3-p327/gems/rack-1.4.1/lib/rack/server.rb:252:in `start'
from /home/amer/.rvm/gems/ruby-1.9.3-p327/gems/railties-3.2.9/lib/rails/commands/server.rb:70:in `start'
from /home/amer/.rvm/gems/ruby-1.9.3-p327/gems/railties-3.2.9/lib/rails/commands.rb:55:in `block in <top (required)>'
from /home/amer/.rvm/gems/ruby-1.9.3-p327/gems/railties-3.2.9/lib/rails/commands.rb:50:in `tap'
from /home/amer/.rvm/gems/ruby-1.9.3-p327/gems/railties-3.2.9/lib/rails/commands.rb:50:in `<top (required)>'
from script/rails:6:in `require'
from script/rails:6:in `<main>'

Before posting here I tried reinstalling ruby 1.9.3. using rvm. I tried using

rvm gemset empty [gemset_name]

as was discribed in RVM: Uninstalling all gems of a gemset but that didn't really help either.

What should I do? Can anyone explain to me what is happening here?

VenkatK · Accepted Answer · 2012-12-04T04:53:45.517

I understood your problem. You have written rails generate devise install. It means that you have associated install as a model to devise rather configure it. So your files have been created with out devise configuration.

You just follow what I have written:
1) Create a devise.rb file in '/config/initializers'
2) Write the following code inside it:

Devise.setup do |config|
  config.mailer_sender = "devise@example.com"
  config.scoped_views = true
  require 'devise/orm/active_record'#[This works for you]
  config.case_insensitive_keys = [ :email ]
  config.strip_whitespace_keys = [ :email ]
  config.skip_session_storage = [:http_auth]
  config.stretches = Rails.env.test? ? 1 : 10
  config.reconfirmable = true
  config.reset_password_within = 6.hours
  config.sign_out_via = :delete
end

2) And write rails destroy devise install in the terminal. Thats it.
I think the above will work for sure.

3) Now start your server again rails s.
4) Install devise again carefully. And go ahead.

Hey! @VenkatK thanks for your answer. I followed your steps, but when I ran `rails destroy devise install` i had what appears to me to be the same error message again. Starting with `/home/amer/.rvm/gems/ruby-1.9.3-p327/gems/activesupport-3.2.9/lib/active_support/inflector/methods.rb:230:in `block in constantize': uninitialized constant Install (NameError)` and so on. — amerdidit, Dec 04 '12 at 10:14
@user1861553 If that is the case again, better removing those files which were created when running `rails destroy devise install` manually. And restart the server. — VenkatK, Dec 04 '12 at 13:08

score 0 · Answer 2 · answered Dec 04 '12 at 01:07

I don't think you have a gem problem, just a confused Devise setup, which is likely easily unconfused.

When you run the Devise generator (with rails generate Devise:something) it runs code to create a few files specific to your application within your application tree (app/*). I am looking at a Devise install and think it's mostly going to be in the app/views/devise directory, but it's possible that it also updates your User model. It definitely updates your app/routes.rb file and creates a file in config/initializers. There may be others.

Delete any of these. There may be other files in locales, db/migrate (there is a migration -- don't run it, or run rake db:rollback before deleting it if you have).

Then re-run the installation.

Another approach if this doesn't work would be to create a new dummy Rails app, install devise there, and see what files get created -- usually generators report what they are doing.

none of those files exist, and it doesn't seem to have changed anything is routes.rb. when i run the ' rake db:rollback' command I get an ininitialised constant devise error. — amerdidit, Dec 04 '12 at 10:32
OK, well I think it's likely that *something* within your Rails app that has been installed by Devise is causing the problem. A close examination of the stack trace suggests either `environment.rb` or `routes.rb` or perhaps a file in the `initializers` directory has been created. @VenkatK may be right that the first incorrect run has attempted to associated Devise with the non-existant model Install, but in any case, you should just remove anything (including the reference to the devise gem from the `Gemfile.rb`) from your app. This is a great use for source control :-) — Tom Harrison, Dec 04 '12 at 13:19

Uninitialized constant error message after a typo done while installing devise gem

2 Answers2