I'm using RubyInline-3.6.2 and am having trouble getting this simple  
example to work.

require 'rubygems'
require 'inline'

class Example
   inline do |builder|
     builder.c "
       int simple() {
         int x = 10;
         return x;
       }"
   end
end

p Example.new.simple

When I run this I get

/usr/local/lib/ruby/gems/1.8/gems/RubyInline-3.6.2/./inline.rb:378:in  
`build': undefined method `+' for nil:NilClass (NoMethodError)
         from /usr/local/lib/ruby/gems/1.8/gems/RubyInline-3.6.2/./ 
inline.rb:628:in `inline'
         from demo.rb:5

I'm not sure if I'm doing something wrong or there is a bug in that  
version of RubyInline.