Unchecked exceptions caused by behavior implementations are silently dropped

Suppose a driver implementing FlowRuleProgrammable has a bug that throws an unchecked exception. No trace of this exception can be found in the log, hence making it very difficult to debug the problem.

For example when I run a command in the CLI to add a flow rule, the operation fails because of a bug in the driver and the command hangs until I press ctrl+C (see attachment). In my case the exception is a NullPointerException, but no trace of this can be found in the log.