Scalatest maven plugin: ERROR: -c has been deprecated for a very long time and is no longer supported
<p>I'm using the <a href="https://mvnrepository.com/artifact/org.scalatest/scalatest-maven-plugin" rel="nofollow">scalatest-maven-plugin</a> latest 1.0 version, with <a href="https://github.com/scalatest/scalatest-maven-plugin" rel="nofollow">source code here</a>. Trying to run my suites in parallel and using the following configuration:</p>

<pre><code>&lt;build&gt;&lt;plugin&gt;
    &lt;groupId&gt;org.scalatest&lt;/groupId&gt;
    &lt;artifactId&gt;scalatest-maven-plugin&lt;/artifactId&gt;
    &lt;version&gt;1.0&lt;/version&gt; 
    &lt;configuration&gt;
        &lt;reportsDirectory&gt;${project.build.directory}/surefire-reports&lt;/reportsDirectory&gt;
        &lt;junitxml&gt;.&lt;/junitxml&gt;
        &lt;filereports&gt;WDF TestSuite.txt&lt;/filereports&gt;
        &lt;htmlreporters&gt;${project.build.directory}/html/scalatest&lt;/htmlreporters&gt;                    
        &lt;parallel&gt;true&lt;/parallel&gt;
    &lt;/configuration&gt;
    &lt;executions&gt;
        &lt;execution&gt;
            &lt;id&gt;test&lt;/id&gt;
            &lt;goals&gt;
                &lt;goal&gt;test&lt;/goal&gt;
            &lt;/goals&gt;
        &lt;/execution&gt;
    &lt;/executions&gt;
&lt;/plugin&gt;&lt;/build&gt;
</code></pre>

<p>leads to the following Maven build error:</p>

<pre><code>[INFO]
[INFO] --- scalatest-maven-plugin:1.0:test (test) @ myproject ---
Exception in thread "ScalaTest-main" java.lang.IllegalArgumentException: ERROR: -c has been deprecated for a very long time and is no longer supported, to prepare for reusing it for a different purpos
e in the near future. Please change all uses of -c to -P.
        at org.scalatest.tools.ArgsParser$.checkArgsForValidity(ArgsParser.scala:46)
        at org.scalatest.tools.Runner$.runOptionallyWithPassFailReporter(Runner.scala:857)
        at org.scalatest.tools.Runner$.main(Runner.scala:827)
        at org.scalatest.tools.Runner.main(Runner.scala)
</code></pre>

<p>Basically the scalatest-maven-plugin is passing <code>-c</code> to the scalatest CLI instead of the correct <code>-P</code> .. or even better <code>-P10</code> i.e. the number of threads to use.</p>

<p>How can I pass the <code>-P10</code> to the scalatest process via Maven? I have tried setting it in the <code>MAVEN_OPTS</code> environment variable or in the Maven CLI directly but it doesn't get picked up.</p>

<p>I have also tried configuring the scalatest-maven-plugin like this:</p>

<pre><code>&lt;configuration&gt;
    &lt;argLine&gt;-P10&lt;/argLine&gt;
&lt;/configuration&gt;
</code></pre>

<p>but this parameter is passed to the java process and not to the Scalatest so it fails too.</p>