I didn't really understand the answer to this question, and the answer to this question didn't work for me.
Running Heroku push got some errors, and running heroku run bundle exec rake assets:precompile
gave all the "can't dump anonymous class" errors.
Here's my Gemfile:
source 'https://rubygems.org'
ruby '2.1.1'
#ruby-gemset=railstutorial_rails_4_0
gem 'rails', '4.0.5'
gem 'bootstrap-sass', '2.3.2.0'
gem 'sprockets', '2.11.0'
gem 'sass-rails'
gem 'sass', '3.2.5'
group :production do
gem 'pg', '0.15.1'
gem 'rails_12factor', '0.0.2'
end
Thanks!