Could not find a JavaScript runtime -- Bundler & Rbenv

I'm trying to deploy my app using Capistrano, Bundler, and Rbenv. When I
execute "cap deploy:update" I get get the following error when trying to

"Could not find a JavaScript runtime. See for a list of available runtimes."

failed: "env
sh -c 'cd /home/ari/www/tutelage/releases/20120504012619 && bundle exec
rake RAILS_ENV=production RAILS_GROUPS=assets assets:precompile'" on

Does anyone know why? My Gemfile includes: execjs and therubyracer

My deploy.rb file includes:

require 'bundler/capistrano'

load 'deploy/assets'

default_run_options[:pty] = true

set :default_environment, { "PATH" =>



AFAIK execjs and rubyracer are not JS runtimes themselves, only
wrappers (though I may be wrong!). I got this error too, installed
NodeJS on my server, and everything worked perfectly, so I made a
conclusion, that NodeJS is suitable JS runtime for Rails:)))