The reason for this is Linux, by default, does not have an interface to a JavaScript engine.
Use one of these methods to install the interface required:
- Add The Ruby Racer gem to your Gemfile assets group:
group :assets do gem 'therubyracer' end
* Its a bit of a memory hog (Heroku discourage it) and you need to add it to every project you spin up on that machine. - Install the Node.js package to your machine:
sudo apt-get install nodejs
* Distro specific installation: Installing Node.js by Package Manager