title: Change bundle install Ruby version
body: <p>I'm new to Ruby/Rails, so forgive me if this is a trivial question. Whenever I run <code>bundle install</code>, it installs everything in vendor/bundle/ruby/1.8 instead of vendor/bundle/ruby/1.9.1, which is the version of Ruby I am using. When I run <code>ruby -v</code>, I get the correct 1.9.1 version, but bundle install insists on 1.8 for some reason, and this is causing many errors with basic Rails functionality. </p>
  
  <p>How do I instruct bundle to work with 1.9.1 (and preferably remove any trace of Ruby 1.8)?</p>
  
  <p>Thanks!</p>
  
  <p>EDIT: I've done everything <a href="https://stackoverflow.com/a/6235916/288037">this</a> answer says, and I get no trace of 1.8</p>
  
  <p>EDIT AGAIN: Well, it's working somehow. Perhaps restarting Bash fixed it. In any case, is there a general solution to forcing <code>bundle install</code> to use a particular version of Ruby, lest this happens again or to someone else?</p>