Rails 4 and Devise setup

Warning: this article may be out of date

If your getting a ActiveModel::ForbiddenAttributesError it might be because you don't have the protected_attributes gem included.

gem 'rails', '4.0.0.beta1'
gem "protected_attributes", "~> 1.0.0"
gem 'devise', git: 'git://github.com/plataformatec/devise.git', branch: 'rails4'