Build wildfly-elytron using mvn clean install -DskipTests=true.

Once the build has finished, build the full JavaDoc using mvn javadoc:aggregate@full-javadoc.

Once that finishes, scroll up in the output to the warnings section. You should see the following warning in RegexRoleMapper:

[WARNING] /home/fjuma/Documents/releases/wildfly-elytron/auth/server/base/src/main/java/org/wildfly/security/authz/RegexRoleMapper.java:68: warning - Tag @return cannot be used in class documentation.  It can only be used in the following types of documentation: method.

Update the JavaDoc in RegexRoleMapper so this warning no longer occurs.