I come into work today to this error:
ActionView::Template::Error ('twitter/bootstrap/bootstrap.less' wasn't found.
Odd...It works in development. What could have happened?
The search
I ran the application locally with the development environment and got the same error. Great, at least it's reproducible. Let's hit the Googles...
Hmm, some mentions in twitter-bootstrap-rails and some scattered StackOverflow questions, but nothing that works. Then I noticed Heroku was no longer precompiling the assets on deploy.
The discovery
The Heroku docs have this glorious quote:
The most common cause of failures in assets:precompile is an app that relies on having its environment present to boot. Your app's config vars are not present in the environment during slug compilation, so you should take steps to handle the nil case for config vars (and add-on resources) in your initializers.
A recent change added some configuration variables in application.rb that referenced some environment variables.
The fix
Based on some more documentation and community help, I moved the configuration into an initializer that is loaded after the slug compilation when it can access the environment variables.
Deploy. Working. #winning.
