Resolved in topic branch https://github.com/scottmarlow/wildfly/tree/WFLY-10520_pr_hack.

Marker support is working, turns out it was working before but adding a marker interface to application classes is not safe, as that can confuse the EJB deployer. Instead, we are adding a class instance field, which works better.

Currently, we can use the globally with system property -DHibernate51CompatibilityTransformer=true or the j-d-s.xml, I'm not sure if it is safe to enable the transformer via both options at the same time, which is why I started working on the https://github.com/scottmarlow/wildfly/tree/WFLY-10520_pr_hack_TransformedMarkerInterface change.

https://github.com/scottmarlow/wildfly/tree/WFLY-10520_pr_hack_TransformedMarkerInterface contains an attempt to add a marker interface but it fails the test so must be missing something.

I pushed test changes to the WFLY-10520_pr_hack branch. I removed the setting of the system property from arquillian.xml and added a j-d-s.xml file that includes the transformer settings.

I should be able to merge the support fro WFWIP-75 after adding a org.jboss.as.hibernate.Transformed marker interface that means that an application class has been transformed, which we will use to avoid transforming the same class more than once.

Applications shouldn't need to add a dependency on org.hibernate.bytecodetransfomer, as we will remove that module in the future.

With my other local changes, the following j-d-s.xml (moved to a separate file) seems to work:

<jboss-deployment-structure>
    <deployment>
        <transformers>
            <transformer class="org.jboss.as.hibernate.Hibernate51CompatibilityTransformer"/>
        </transformers>
        <dependencies>
            <module name="com.h2database.h2" />
            <module name="org.slf4j"/>
        </dependencies>
    </deployment>
    <sub-deployment name="beans.jar">
        <transformers>
            <transformer class="org.jboss.as.hibernate.Hibernate51CompatibilityTransformer"/>
        </transformers>
    </sub-deployment>
    <sub-deployment name="main.war">
        <transformers>
            <transformer class="org.jboss.as.hibernate.Hibernate51CompatibilityTransformer"/>
        </transformers>
    </sub-deployment>

</jboss-deployment-structure>