title: How to exclude a module from a Maven reactor build?
body: <p>We have a Maven 2 project with lots of modules in it. Example:</p>
  
  <pre><code>&lt;modules&gt;
    &lt;module&gt;common&lt;/module&gt;
    &lt;module&gt;foo&lt;/module&gt;
    &lt;module&gt;data&lt;/module&gt;
    &lt;module&gt;bar&lt;/module&gt;
    ... more ...
  &lt;/module&gt;
  </code></pre>
  
  <p>Let's say the "data" module is time consuming to build and we want to exclude it when the project is build by a CI server. Currently we use two pom.xml files to achieve this. One has all modules in it and the other one has all modules except the ones which can be left out for CI. But that's pretty annoying because sometimes we forget to put a new module into <strong>both</strong> files. </p>
  
  <p>Is there a solution which doesn't need two separate module lists?</p>