title: Ant failing with Content is not allowed in prolog
body: <p>I am using subant and it is resulting into <em>Content is not allowed in prolog</em> problem.</p>
  
  <pre><code>    &lt;subant target="main" genericantfile="build.xml"&gt;
          &lt;fileset dir = "." /&gt;
      &lt;/subant&gt;
  </code></pre>
  
  <p>Error:</p>
  
  <pre><code>The following error occurred while executing this line:
  pattern.py:1: Content is not allowed in prolog.
  </code></pre>
  
  <p>Please note I have different files in those folders for example, python files.</p>
  
  <p>When I use explicit listing using the filelist, all works fine.</p>
  
  <pre><code>&lt;subant target="main" genericantfile="build.xml"&gt;                
        &lt;filelist dir="." 
             files = "A/build.xml,
                      B/build.xml"
     /&gt;
  &lt;/subant&gt;
  </code></pre>