To upgrade v2 from any other version:

In your JavaScript manifest, remove the following:

# app/assets/javascripts/application.js

#= require base
#= require_tree ./utilities
#= require_tree ./elements

If you have an initializer file, config/initializers/rails_script.rb, delete it. Support for custom namespaces has been dropped.

Now you can run the installer again, this will add #= require rails_script to your manifest.

bin/rails g rails_script:install