Does this still work?

I've added

io.output():setvbuf('no')

to main.lua, built the project for device, deployed it to the device with the Xcode organiser and I get nothing when running the app. No print statements, no lua errors (thinking about it, those aren't going to show up even if this was working).

Have I missed a step or does this just not work any more?

I've got a fairly random freeze which is connected to the native keyboard which I'm trying to track down.