Rails 3.1.1 never depends on bcrypt-ruby, but must be required.

One week ago, Ruby on Rails 3.1.1 has been released. Since this release, rails never depends on bcrypt-ruby. But, when you use some functions related with encryption, you need to choice from some encryption gems.

For example, if you want to use has_secure_password, you should write onto Gemfile like below:

gem 'bcrypt-ruby', '~> 3.0.0'