Devise Secret Key was not set

Question

I am developing a Rails 4 app using the Active Admin gem for the administration back end. Active Admin in turn uses Devise for user authentication. Now, when I try to deploy

Answer 1

I ran bundle update this morning and started getting the same error.

I added it as a line in config/initializers/devise.rb and the error was fixed.

This seems to be the commit which introduced it.