title: Mutiple maven plugin executions with different system property values
body: <p>I am trying to execute the plugin below more than once with a different value of a system property called <code>testVar</code>. I have the following plugin in my <code>pom.xml</code>:</p>
  
  <pre><code>&lt;plugin&gt;
      &lt;groupId&gt;org.apache.maven.plugins&lt;/groupId&gt;
      &lt;artifactId&gt;maven-surefire-plugin&lt;/artifactId&gt;
      &lt;version&gt;2.14.1&lt;/version&gt;
      &lt;configuration&gt;
          &lt;skip&gt;false&lt;/skip&gt;
          &lt;forkCount&gt;1&lt;/forkCount&gt;
          &lt;threadCount&gt;3&lt;/threadCount&gt;
      &lt;/configuration&gt;
      &lt;executions&gt;
          &lt;execution&gt;
              &lt;id&gt;before-run&lt;/id&gt;
              &lt;goals&gt;
                  &lt;goal&gt;test&lt;/goal&gt;
              &lt;/goals&gt;
              &lt;configuration&gt;
                  &lt;systemPropertyVariables&gt;
                      &lt;testVar&gt;aaa&lt;/testVar&gt;
                  &lt;/systemPropertyVariables&gt;
              &lt;/configuration&gt;
          &lt;/execution&gt;
          &lt;execution&gt;
              &lt;id&gt;main-run&lt;/id&gt;
              &lt;goals&gt;
                  &lt;goal&gt;test&lt;/goal&gt;
              &lt;/goals&gt;
              &lt;configuration&gt;
                  &lt;systemPropertyVariables&gt;
                      &lt;testVar&gt;bbb&lt;/testVar&gt;
                  &lt;/systemPropertyVariables&gt;
              &lt;/configuration&gt;
          &lt;/execution&gt;
      &lt;/executions&gt;
  &lt;/plugin&gt;
  </code></pre>
  
  <p>I am getting <code>null</code> when running <code>System.getProperty("testVar")</code>. However, I can access the <code>testVar</code> properly when it is declared at the plugin-level. What's wrong?</p>