title: Checking an environment variable using the Maven AntRun plugin
body: <p>I'm trying to check and see if the MULE_HOME environment variable is set within the maven-antrun-plugin without success.  Here's what I have so far:</p>
  
  <pre><code>&lt;plugin&gt;
              &lt;groupId&gt;org.apache.maven.plugins&lt;/groupId&gt;
              &lt;artifactId&gt;maven-antrun-plugin&lt;/artifactId&gt;
              &lt;version&gt;1.7&lt;/version&gt;
              &lt;executions&gt;
                  &lt;execution&gt;
                      &lt;id&gt;mule-deploy&lt;/id&gt;
                      &lt;phase&gt;install&lt;/phase&gt;
                      &lt;goals&gt;
                          &lt;goal&gt;run&lt;/goal&gt;
                      &lt;/goals&gt;
                      &lt;configuration&gt;
                          &lt;target&gt;
                              &lt;taskdef resource="net/sf/antcontrib/antcontrib.properties"
                                       classpath="${settings.localRepository}/ant-contrib/ant-contrib/1.0b3/ant-contrib-1.0b3.jar"/&gt;
                              &lt;echo message="MULE_HOME is ${env.MULE_HOME}"/&gt;
                              &lt;if&gt;
                                  &lt;isset property="env.MULE_HOME"/&gt;
                                  &lt;then&gt;
                                      &lt;echo message="MULE_HOME is set"/&gt;
                                  &lt;/then&gt;
                                  &lt;else&gt;
                                      &lt;echo message="MULE_HOME is not set"/&gt;
                                  &lt;/else&gt;
                              &lt;/if&gt;
                          &lt;/target&gt;
                      &lt;/configuration&gt;
                  &lt;/execution&gt;
              &lt;/executions&gt;
  &lt;/plugin&gt;
  </code></pre>
  
  <p>The output is:</p>
  
  <pre><code> [echo] MULE_HOME is /&lt;my development path&gt;/mule
   [echo] MULE_HOME is not set
  </code></pre>
  
  <p>What am I missing to check an environment variable?</p>