The unit tests don't run when org.gradle.parallel=true is set (which is the default).  The tests are in contention over port 9000 which is the Quarkus management port.  The error message is

java.lang.RuntimeException: java.lang.RuntimeException: Failed to start quarkus
Caused by: java.lang.RuntimeException: Failed to start quarkus
Caused by: java.lang.RuntimeException: Unable to start HTTP server
Caused by: java.util.concurrent.ExecutionException: java.lang.IllegalStateException: Unable to start the management interface
Caused by: java.lang.IllegalStateException: Unable to start the management interface
Caused by: java.net.BindException: Address already in use