title: maven surefire: when are we forced to set reuseForks=false?
body: <p>In my project when I set <strong>reuseForks=true</strong> then i have to increase the forkCount to number of test classes. Otherwise, It is throwing illegalargument exception. 
  Also, If I set <strong>reuseForks=false</strong> then it also work fine. </p>
  
  <p>Currently I have following configuration because number of test classes are less than 10. </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;2.18.1&lt;/version&gt;
              &lt;configuration&gt;
                  &lt;reuseForks&gt;true&lt;/reuseForks&gt;
                  &lt;forkCount&gt;10&lt;/forkCount&gt;
              &lt;/configuration&gt;
          &lt;/plugin&gt;
  </code></pre>
  
  <p>How can I keep <strong>reuseFork=true</strong> and <strong>forkCount=1</strong>.</p>
  
  <p>EDIT: StackTrace on reuseFork=true and forkCount=1</p>
  
  <pre><code>    checkForReturnEventsPresent on checkForReturnEventsPresent(com.eras.senders.OMSReturnEventDataSenderTest)(com.eras.senders.OMSReturnEventDataSenderTest)  Time elapsed: 0.014 sec  &lt;&lt;&lt; FAILURE!
  java.lang.IllegalArgumentException: null
      at org.apache.maven.surefire.testng.TestNGExecutor.run(TestNGExecutor.java:115)
      at org.apache.maven.surefire.testng.TestNGDirectoryTestSuite.executeMulti(TestNGDirectoryTestSuite.java:212)
      at org.apache.maven.surefire.testng.TestNGDirectoryTestSuite.execute(TestNGDirectoryTestSuite.java:108)
      at org.apache.maven.surefire.testng.TestNGProvider.invoke(TestNGProvider.java:111)
      at org.apache.maven.surefire.booter.ForkedBooter.invokeProviderInSameClassLoader(ForkedBooter.java:203)
      at org.apache.maven.surefire.booter.ForkedBooter.runSuitesInProcess(ForkedBooter.java:155)
      at org.apache.maven.surefire.booter.ForkedBooter.main(ForkedBooter.java:103)
  </code></pre>