I'm very new to Rails, and I'm trying to build a user authentication system with 'devise', but I am failing. I'm following Rails Girls Guides's tutorial on adding authentication using the gem 'devise'. Once I got to step 5, which is to set up the User model, I received this error after running rake db:migrate
rake aborted!
NoMethodError: undefined method `merge!' for #<ActionDispatch::Routing::Mapper::Scope:0x007fd3397a7448>
/Users/.rvm/gems/ruby-2.1.2/gems/devise-3.0.4/lib/devise/rails/routes.rb:420:in `ensure in with_devise_exclusive_scope'
/Users/.rvm/gems/ruby-2.1.2/gems/devise-3.0.4/lib/devise/rails/routes.rb:420:in `with_devise_exclusive_scope'
/Users/.rvm/gems/ruby-2.1.2/gems/devise-3.0.4/lib/devise/rails/routes.rb:233:in `block (2 levels) in devise_for'
/Users/.rvm/gems/ruby-2.1.2/gems/devise-3.0.4/lib/devise/rails/routes.rb:336:in `block in devise_scope'
Has anyone solved this error? I've looked at all solutions such as not generating user model before installing devise, running bundle install, running rails g devise:install, and more. Nothing has worked so far when I'm trying to use devise for Rails 4.0.
Also, does anyone have recommendations on what tutorials I can follow to build an authentication system? I've tried a lot so far, and none has worked.