I have an issue with running the rails console at heroku (cedar-stack). Each of the following commands heroku run console, heroku run rails console, heroku run bundle exec rails
For some reason you need to explicitly define the console process in the Procfile:
Procfile
# Procfile web: script/rails server -p $PORT console: script/rails console
This blog post has more details: http://platypus.belighted.com/blog/2013/01/21/ruby-2-rails-4-heroku/