title: How do I set/get session vars in a Rack app?
body: <pre><code>use Rack::Session::Pool
  ...
  session[:msg]="Hello Rack"
  </code></pre>
  
  <p>EDIT: The word session doesn't seem to resolve. I included the Session pool middleware in my config.ru, and try to set a variable in an ERB file (I'm using Ruby Serve) and it complains "undefined local variable or method `session'"</p>
  
  <p>Thanks!</p>