rails/rails — pull request #4405 by brentsowers1 (2012-01-11 04:49:51+00:00)
Title: therubyracer gem is now added to the Gemfile on systems that do not have...

... a Javascript runtime (Linux without node js). Without this gem an error is reported by execjs

Issues #412 and #4020

I've tested this on Ubuntu with and without nodejs, and on Windows, and it works correctly, the Gemfile contains a line for therubyracer only on Ubuntu without nodejs