title: How to change the ant directory to excute ant task from different folder
body: <p>There are two build files placed in different folder </p>
  
  <p><code>folder1/build.xml</code></p>
  
  <p><code>folder1/subfolder/sub/build.xml</code></p>
  
  <p>I am having exectable task in <code>folder1/build.xml</code> </p>
  
  <pre><code>&lt;exec dir="." executable="${tools.versionupdater.exe}" failonerror="true"&gt;
    &lt;arg value="${dist.path}" /&gt;
    &lt;arg value="${build.version}" /&gt;
    &lt;arg value="${build.version}" /&gt;
  &lt;/exec&gt;
  </code></pre>
  
  <p>which is running properly because which can find <code>visionupdater.exe</code> that is placed in <code>folder1/tools/VersionUpdater/versionupdater.exe</code> under same root folder.</p>
  
  <p>How can I run the <code>versionupdater.exe</code> from another build file 
  which is placed in <code>folder1/subfolder/sub/build.xml</code>?</p>