Can I debug node 8 from the command line, or do I need X / chrome now?

You can also debug, to a limited degree, from the command line:

https://nodejs.org/api/debugger.html

> Node.js's debugger client is not a full-featured debugger, but simple step and inspection are possible.

Thanks. I use the REPL debugger often, glad to see it's not going away.

Note: --debug-brk has been deprecated in Node 8, you can use --inspect-brk (--inspect not needed) instead.