It would appear this is just related to a bad configuration. Specifically the test is not specifying either:

1. The JtaPlatform to use
2. The TransactionCoordinatorBuilder to use.

Note specifically in the reported stacktrace:

        at org.hibernate.resource.transaction.backend.jdbc.internal.DdlTransactionIsolatorNonJtaImpl.getIsolatedConnection(DdlTransactionIsolatorNonJtaImpl.java:51)

Scott Marlow was going to try to verify that changing those config options resolved the failure.