title: Debugging AIR: ADL fails to launch
body: <p>I've hit a snag when trying to debug an AIR app using <code>adl</code>.</p>
  
  <p>Although <code>adl</code> successfully launches, the application never appears on screen / starts up.</p>
  
  <p>eg:</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt;
  &lt;s:WindowedApplication xmlns:fx="http://ns.adobe.com/mxml/2009" 
                         xmlns:s="library://ns.adobe.com/flex/spark" 
                         xmlns:mx="library://ns.adobe.com/flex/mx"
                         width="400" height="400"
                         preinitialize="trace('hello')"&gt;
      &lt;s:Label text="Hello, world" /&gt;
  &lt;/s:WindowedApplication&gt;
  </code></pre>
  
  <p>When launching this, the <code>trace</code> is never executed, and the application never appears on-screen.</p>
  
  <p>Other points of interest:</p>
  
  <ul>
  <li>The <code>adl</code> debugger does start (ie., I see it's icon in my dock)</li>
  <li>I've tried this with adt from AIR 2.6 and AIR 2.7</li>
  <li>This <em>used</em> to work on my machine, and has suddenly stopped (see below)</li>
  <li>It makes no difference if I launch from Flash Builder, or by invoking the <code>adt</code> command line directly</li>
  <li>I'm on a mac, running OSX 10.6.7</li>
  <li>After this stopped working, I tried installing the FB 4.5.1 upgrade patch, in the hope that this would also update any local framework / SDK files to the latest version.  This had no effect.</li>
  </ul>
  
  <p>As I mentioned above, This used to work fine, and appears to have stopped.</p>
  
  <p>Around the time that things stopped working, I was doing debugging on another app, which involved installing a firewall to block specific ports.  I suspect it may be related to this.</p>
  
  <p>However, I've since uninstalled all firewalls, and it still doesn't work.  I'm not sure which port <code>adt</code> uses, but I don't see it attempting to connect when running <code>lsof -i -n -P</code>.</p>
  
  <p>Any suggestions?</p>
  
  <p><strong>Update</strong>:  I've also since uninstalled and reinstalled Flash Builder (and therefore, the AIR SDK), and it still doesn't work.  I think this adds weight to the port conflict, but still leaves me unsure of where / how to proceed</p>
  
  <p><strong>Further update</strong>  Compiling exactly the same codebase to a AIR installer, installing, and running the application works fine.  (Ie., a production release).  However, the codebase fails to launch with <code>adl</code>.  This pretty much confirms the issue as a local machine config problem somewhere with <code>adl</code>, and not an issue with the codebase.</p>