This gem will rebuild your .gems file for Heroku to match the current contents of your Isolate file each time it is loaded.

Recommended installation is:

# Isolate
gem "isolate-heroku"

# early in your app loading cycle
require "isolate/now"
require "isolate/heroku"

Note that this plugin will only make changes to your local .gems file, you still need to commit it yourself.

See www.jbarnette.com/2010/06/26/isolate-on-heroku.html for original motivation.