title: phantomjs: unknown module system
body: <p>Phantomjs version 1.4 (the newest version available through apt). I have a single js file, with this content:</p>
  
  <pre><code>var page = require('webpage').create();
  var system = require('system');
  </code></pre>
  
  <p>When I run it, with:</p>
  
  <pre><code>phantomjs testscript.js
  </code></pre>
  
  <p>I get the error:</p>
  
  <pre><code>undefined:0 Unknown module system for require()
  </code></pre>
  
  <p>What does this mean? What causes it? I was trying to run the example from <a href="https://github.com/ariya/phantomjs/blob/master/examples/direction.js" rel="nofollow">https://github.com/ariya/phantomjs/blob/master/examples/direction.js</a>, but I can't seem to get the simplest thing to work. Is there another way to read command line arguments than using system?</p>