title: Groovy Eclipse compiler plugin for maven not compiling anything
body: <p>I'm trying to understand the correct setup of a Java and Groovy project in Maven, compiling the source files with groovy-eclipse-compiler.</p>
  
  <p>According to the <a href="http://groovy.codehaus.org/Groovy-Eclipse+compiler+plugin+for+Maven" rel="noreferrer">plugin site</a>, if you have files in <code>src/main/java</code> and <code>src/test/java</code> the compiler should find both Java and Groovy by default.</p>
  
  <p>Setting up the <code>build</code> like the example makes <code>target/classes</code> empty.</p>
  
  <pre><code>&lt;build&gt;
  ...
  &lt;plugins&gt;
    &lt;plugin&gt;
      &lt;artifactId&gt;maven-compiler-plugin&lt;/artifactId&gt;
      &lt;version&gt;2.3.2&lt;/version&gt;
      &lt;configuration&gt;
        &lt;compilerId&gt;groovy-eclipse-compiler&lt;/compilerId&gt;
        &lt;!-- set verbose to be true if you want lots of uninteresting messages --&gt;
        &lt;!-- &lt;verbose&gt;true&lt;/verbose&gt; --&gt;
      &lt;/configuration&gt;
      &lt;dependencies&gt;
        &lt;dependency&gt;
          &lt;groupId&gt;org.codehaus.groovy&lt;/groupId&gt;
          &lt;artifactId&gt;groovy-eclipse-compiler&lt;/artifactId&gt;
          &lt;version&gt;2.7.0-01&lt;/version&gt;
        &lt;/dependency&gt;
      &lt;/dependencies&gt;
    &lt;/plugin&gt;
    ...
  &lt;/plugins&gt;
  &lt;/build&gt;
  </code></pre>
  
  <p>The only way I found to make it work was to use the <code>build-helper-maven-plugin</code>. This is the option used by the Archetype too:</p>
  
  <pre><code>mvn archetype:generate \
      -DarchetypeGroupId=org.codehaus.groovy \
      -DarchetypeArtifactId=groovy-eclipse-quickstart \
      -DarchetypeVersion=2.5.2-SNAPSHOT \
      -DgroupId=foo \
      -DartifactId=bar \
      -Dversion=1 \
      -DinteractiveMode=false \
      -DarchetypeRepository=https://nexus.codehaus.org/content/repositories/snapshots/
  </code></pre>
  
  <p>So, it's the page outdated? Isn't enough have Java files in the src folder?</p>