Turing is currently experiencing time-out issues when trying to redirect. You can see this by trying to visit turing.mybinder.org. At the moment, I'm at a loss as to the cause. All nodes are healthy and nothing suspicious in the hub logs.
This was fixed by forced deleting some hanging user pods in Completed and Terminating states. I'm not sure why those two things are linked though!
Force deletion command used:
kubectl delete pods <pod_name> --grace-period=0 --force -n turing
Thanks for the debug and the post-mortem notes :-)