autodetect': Could not find a JavaScript runtime


I was working with Railinstaller, but everytime i turned around I found something new had changed. Soo I thought I would give Ubuntu a try . I do like unix better then window. anyway… I created a new project then went to run rail server only to find this error - autodetect’: Could not find a JavaScript runtime.

I cant seem to get around this problem - any thoughts

Thanks in advance


Include rubyracer and execjs gems in ur gemfile install the bundle and go for it.

Have a look at the Rails Guide on Getting Started. Section 4.1
explains what this is about.


Is there somewhere that explains the new updates to gem files like needing rubyracer or execjs - like what things have changed? When I first started working with rails about 4 months ago there was no need for


I looked and didn't see much either. Ended up running `apt-get
install nodejs` to make it stop complaining. Seems like they are
assuming a lot about anyone's particular website needs these days.
"Your website doesn't have a server side js backend? You are so

$ sudo apt-get install nodejs

This will remove your problem.