title: Error when trying to Sandbox with codesign command
body: <p>I am trying to Sandbox my OS X app using the <code>codesign</code> command (this is a common lisp app and does not use Xcode).  I have created a very basic enitlements plist that looks like this:</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt;
  &lt;plist version="1.0"&gt;
      &lt;dict&gt;
          &lt;key&gt;com.apple.security.app-sandbox&lt;/key&gt;
          &lt;true/&gt;
      &lt;/dict&gt;
  &lt;/plist&gt;
  </code></pre>
  
  <p>and I am calling the <code>codesign</code> command:</p>
  
  <pre><code>codesign -s - -f --entitlements "/path/to/my/app/MyApp.app/Contents/entitlements.plist" "/path/to/my/app/MyApp.app/"
  </code></pre>
  
  <p>But this command returns the following error:</p>
  
  <pre><code>/path/to/my/app/MyApp.app/Contents/entitlements.plist: cannot read entitlement data
  </code></pre>
  
  <p>Does this error mean that I have used the wrong command?  If so what is wrong with the command?</p>