title: maven profile activation based on existence of several files
body: <p>I would like to activate a profile based on the existence of several files. In the following example I want the profile to be activated if both files <code>my.marker</code> and <code>another.marker</code> exists.</p>
  
  <pre><code>    &lt;activation&gt;
          &lt;file&gt;
              &lt;exists&gt;${basedir}/my.marker&lt;/exists&gt;
              &lt;exists&gt;${basedir}/another.marker&lt;/exists&gt;
          &lt;/file&gt;
      &lt;/activation&gt;
  </code></pre>
  
  <p>It does not work since it's not valid against the schema. Is there a way to do such a thing without using command line properties?</p>