title: Maven clean failing to delete files
body: <p>Attempting to configure the maven clean plugin to remove additional directories in my project but it is not working properly. Here is a trivial reproduction using maven 3.5.</p>
  
  <p>Get started with the simple demo app: <a href="https://maven.apache.org/guides/getting-started/maven-in-five-minutes.html" rel="nofollow noreferrer">https://maven.apache.org/guides/getting-started/maven-in-five-minutes.html</a></p>
  
  <p>Modify the <code>pom.xml</code> to configure <code>maven-clean-plugin</code>:</p>
  
  <pre><code>&lt;project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"&gt;
      &lt;modelVersion&gt;4.0.0&lt;/modelVersion&gt;
      &lt;groupId&gt;com.mycompany.app&lt;/groupId&gt;
      &lt;artifactId&gt;my-app&lt;/artifactId&gt;
      &lt;version&gt;1.0-SNAPSHOT&lt;/version&gt;
      &lt;packaging&gt;jar&lt;/packaging&gt;
      &lt;name&gt;Maven Quick Start Archetype&lt;/name&gt;
      &lt;url&gt;http://maven.apache.org&lt;/url&gt;
      &lt;build&gt;
          &lt;plugins&gt;
              &lt;plugin&gt;
                  &lt;artifactId&gt;maven-clean-plugin&lt;/artifactId&gt;
                  &lt;version&gt;3.0.0&lt;/version&gt;
                  &lt;executions&gt;
                      &lt;execution&gt;
                          &lt;id&gt;auto-clean&lt;/id&gt;
                          &lt;phase&gt;clean&lt;/phase&gt;
                          &lt;goals&gt;
                              &lt;goal&gt;clean&lt;/goal&gt;
                          &lt;/goals&gt;
                          &lt;configuration&gt;
                              &lt;verbose&gt;true&lt;/verbose&gt;
                              &lt;fieldsets&gt;
                                  &lt;fieldset&gt;
                                      &lt;directory&gt;${basedir}&lt;/directory&gt;
                                      &lt;includes&gt;
                                          &lt;include&gt;demo/**&lt;/include&gt;
                                      &lt;/includes&gt;
                                  &lt;/fieldset&gt;
                              &lt;/fieldsets&gt;
                          &lt;/configuration&gt;
                      &lt;/execution&gt;
                  &lt;/executions&gt;
              &lt;/plugin&gt;
          &lt;/plugins&gt;
      &lt;/build&gt;
      &lt;dependencies&gt;
          &lt;dependency&gt;
              &lt;groupId&gt;junit&lt;/groupId&gt;
              &lt;artifactId&gt;junit&lt;/artifactId&gt;
              &lt;version&gt;4.8.2&lt;/version&gt;
              &lt;scope&gt;test&lt;/scope&gt;
          &lt;/dependency&gt;
      &lt;/dependencies&gt;
  &lt;/project&gt;
  </code></pre>
  
  <p>Create a dummy directory called <code>demo</code></p>
  
  <pre><code> mkdir demo &amp;&amp; touch demo/hello
  </code></pre>
  
  <p>Now run:</p>
  
  <pre><code> mvn package
   mvn clean
  </code></pre>
  
  <p>You'll notice the <code>demo</code> directory is still present. I do not know why this is. I have read these SO articles:</p>
  
  <ul>
  <li><a href="https://stackoverflow.com/questions/18637626/remove-or-delete-resource-files-from-target-directory-using-pom-file">Remove or delete resource files from target directory using pom file</a></li>
  <li><a href="https://stackoverflow.com/questions/25822100/maven-clean-not-deleting-files">Maven clean not deleting files</a></li>
  <li><a href="https://stackoverflow.com/questions/20901205/maven-clean-not-working">Maven clean not working</a></li>
  </ul>
  
  <p>and I have tried running different permutations of the goal, phase, and id:</p>
  
  <ul>
  <li><code>clean</code></li>
  <li><code>clean:clean</code></li>
  <li><code>clean:auto-clean</code></li>
  </ul>
  
  <p>and so on to no avail...</p>
  
  <p>I did a simple sanity check to see what was passed to the mojo:</p>
  
  <pre><code>[DEBUG] Configuring mojo org.apache.maven.plugins:maven-clean-plugin:3.0.0:clean from plugin realm ClassRealm[plugin&gt;org.apache.maven.plugins:maven-clean-plugin:3.0.0, parent: sun.misc.Launcher$AppClassLoader@55f96302]
  [DEBUG] Configuring mojo 'org.apache.maven.plugins:maven-clean-plugin:3.0.0:clean' with basic configurator --&gt;
  [DEBUG]   (f) directory = /Users/djthomps/Desktop/test/target
  [DEBUG]   (f) excludeDefaultDirectories = false
  [DEBUG]   (f) failOnError = true
  [DEBUG]   (f) followSymLinks = false
  [DEBUG]   (f) outputDirectory = /Users/djthomps/Desktop/test/target/classes
  [DEBUG]   (f) reportDirectory = /Users/djthomps/Desktop/test/target/classes
  [DEBUG]   (f) retryOnError = true
  [DEBUG]   (f) skip = false
  [DEBUG]   (f) testOutputDirectory = /Users/djthomps/Desktop/test/target/test-classes
  [DEBUG]   (f) verbose = true
  [DEBUG] -- end configuration --
  </code></pre>
  
  <p>and it looks like my configuration options are never set. Why?</p>
  
  <p>Note: I have read the plugin documentation as well: <a href="https://maven.apache.org/plugins/maven-clean-plugin/examples/delete_additional_files.html" rel="nofollow noreferrer">https://maven.apache.org/plugins/maven-clean-plugin/examples/delete_additional_files.html</a>. From what I understand what I want to do is possible.</p>