how does Hobix select among installed versions of Ruby?

[ed piman]

I have a Powerbook which came with Ruby installed at /usr/bin/ruby and I have a
more recent version at /usr/local/bin/ruby.  I installed Hobix and my first
attemp at a post resulted in this error:

/usr/lib/ruby/site_ruby/1.8/hobix/out/quick.rb:92:in `load': Error `undefined
method `to_html' for nil:NilClass' in erb
/Users/joe/hobix/mathdad/skel/entry.html.quick. (Hobix::Out::QuickError)   

I suspect Hobix is using the older Ruby; I want it to use the newer one. How can
  I accomplish that? I am utterly new to Ruby, so please bear with me...

On the other hand, perhaps I am barking up the wrong tree. What I would like is
to  get past this error on posting. Any advice would be appreciated.

Thanks,

Ed Piman