> running non-compiling Java code yet

I don't mean to sound rude here, but that just sounds like nonsense to me. How are you supposed to run code that won't compile? Does eclipse just generate random bytecodes for the party that doesn't compile?

> debug and run a single failing unit test

I'm not sure where the issue is for you, but this has always been available since I have used IntelliJ, going back 15 years.