Can't Get a Javascript Runtime Installed/Recognized in RedHat (for Rails 3.1)

Trying to setup a production deployment on a dedicated box running RedHat (64bit):

# cat /etc/redhat-release 
Red Hat Enterprise Linux Server release 5.6 (Tikanga)

For the life of me, I can't get a Javascript Runtime installed and/or recognized by my Rails 3.1.0rc6 app.

I've done a gem install of execjs, therubyracer, libv8, and mustang ... still get this error after restarting:

ActionView::Template::Error (Could not find a JavaScript runtime. See https://github.com/sstephenson/execjs for a l开发者_开发技巧ist of available runtimes.
  (in /var/www/demo-setup/releases/20110825184931/app/assets/javascripts/demos.js.coffee)):

Also installed node.js but still get this error.

Any ideas?

---

I don't know what the solution is, but maybe this will help:

The error is being thrown from ExecJS here. If therubyracer gem is installed, then it should be detected by the line require "v8" here.

Can you require "v8" successfully from irb? If so, then that tells you that Rails is being run on a different set of gems somehow. Are you using rvm?