I have a Rails 4 application with
<%= javascript_include_tag \"modernizr\", \"data-turbolinks-track\" => true %>
in the head. In deve
It may be because this file needs to be in /vendor/assets/javascript instead of /app/assets/javascript. The Vendor folder is for javascript libraries, and the App folder is for your code.
A better solution than adding a tag to your layout would be adding a script reference to your application.js and let the sass compiler compress and attach it to your main javascript file.
If you don't get a definitive answer, check out: http://guides.rubyonrails.org/asset_pipeline.html#asset-organization