setting MAVEN_OPTS in environment variables does not work

per the documentation:

Any VM specific option that you want to pass to the executed class must be passed to the Maven VM using the MAVEN_OPTS environment variable.

so I did just that:

    <configuration>
...
                <environmentVariables>
            <MAVEN_OPTS>--enable-preview --add-modules jdk.incubator.vector -ea </MAVEN_OPTS>
          </environmentVariables>
            </configuration>
                </execution>

except that it does not work.

Start with the linked exec-maven-plugin usage documentation and the configuration shown in the issue, then reproduce the environmentVariables setup in a small Maven build. Trace whether MAVEN_OPTS reaches the Maven VM or the executed class; done means the documented VM options are applied to the executed class, with a regression test if the project provides an appropriate test location.