title: Unable to locate Source XRef to link to
body: <p>I have a big maven project that uses the pmd plugin for code quality checks.</p>
  
  <p>since I started using the pmd plugin i get the following warning message:</p>
  
  <pre><code>[WARNING] Unable to locate Source XRef to link to - DISABLED
  </code></pre>
  
  <p>I googled and found that i need to implement the jxr plugin.</p>
  
  <p>so I add the following to the build property in the main pom.xml file.</p>
  
  <pre class="lang-xml prettyprint-override"><code>  &lt;plugin&gt;
      &lt;groupId&gt;org.apache.maven.plugins&lt;/groupId&gt;
      &lt;artifactId&gt;maven-jxr-plugin&lt;/artifactId&gt;
      &lt;version&gt;2.3&lt;/version&gt;
    &lt;/plugin&gt;
  </code></pre>
  
  <p>welp it doesn't really change anything. </p>
  
  <p>any ideas what I need to implement in order to resolve this warning message?</p>
  
  <p>output of <code>mvn -version</code></p>
  
  <pre><code>Apache Maven 3.0.4 (r1232337; 2012-01-17 10:44:56+0200)
  Maven home: /usr/share/maven-bin-3.0
  Java version: 1.7.0_05, vendor: Oracle Corporation
  Java home: /usr/lib64/icedtea7/jre
  Default locale: en_US, platform encoding: ANSI_X3.4-1968
  OS name: "linux", version: "3.5.2-gentoo", arch: "amd64", family: "unix"
  </code></pre>
  
  <p>thanks!</p>