title: Node spawn stdout undefined
body: <p>I have this code:</p>
  
  <pre><code>Printer.prototype.watch = function() {   
    var self = this;   var args = ["-P", this.name];
    var lpq = spawn('lpq', args);
  
    lpq.stdout.on("data", function(data) {
      (some irrelevant code)   
    });
  
    lpq.on("exit", function() {
      self.watch();   
    }); 
  };
  </code></pre>
  
  <p>After some recursive calls, <code>spawn('lpq', args)</code> returns a object with <code>stdout=undefined</code>. Why is this happening?</p>