title: Controlling ruby version used in Rails
body: <p>I have an app using Rails 3.0.6 which I run on two machines. I started with ruby 1.8.7 and recently installed ruby 1.9. I swapped my link in '/usr/bin/ruby' to point to the 1.9 install. When I run 'ruby --version' I get the 1.9. However, in my rails app, when I check 'RUBY_PLATFORM' it shows rails is running with 1.8.7.</p>
  
  <p>How do I tell Rails which ruby environment to use? Strangely, this is not the easiest thing to search for. Probably because I don't know enough about it to form a specific question.</p>