Celluloid::Task::TerminatedError when terminating queue

[system123]

When calling ElectricSlide.shutdown_queue @ref at the end of my cleanup sequence I end up with the following error message:

https://gist.github.com/system123/53343b33329db50646d5579e82bb6324

It should be noted that before calling ElectricSlide.shutdown_queue @ref I ensure all agents and calls in the queue have had hangup called on them first.