When a client invokes method singleClass() on org.jboss.jandex.Index and provides an argument that represents module-info.class, the method fails with NoSuchElements exception. This is caused by an assumption that a map holding known classes is never empty and therefore it is safe to call .iterator().next():

In my case it occurs in WildFly 33.0.1, while trying to examine bean archive candidate Wicket-CDI 10.1.0; the deployment attempt is immediately aborted. When I manually deleted module-info.class from the Wicket-CDI JAR file, the deployment worked as expected. (The mentioned version of WildFly contains Jandex version 3.2.0 within its system modules.)

I believe the correct response would be to return null.