The ruby code uses the Inline gem which allows you to write inline C code in your application for better performance. The code itself includes this line:
In transferring it to a new machine (linux in this case - Fedora and Ubuntu machines in fact) I would get the error "undefined method 'inline'".
I figured this meant I did not have the 'inline' gem so I ran 'sudo gem install inline'. But after that I still got the same error... WRONG GEM! I finally figured out that I want to install RubyInline not inline... plus you also need the hoe gem
$ sudo gem install RubyInline
$ sudo gem install hoe
Tried running the app and this time I got:
ERROR: Can't find header dir for ruby, Exiting...
This tells me that I need a development version of Ruby with all the header files. A regular ruby install does not give you this.
On Mac OS X you need to install the Xcode developer tools.
On Ubuntu you need to do this:
$ sudo apt-get install ruby-dev
On Fedora you would do:
$ sudo yum install ruby-devel
Try it once more and it should work!