debugger (ie. node inspect). watch(<variabe>) says it's not defined, but it is. Am I not using this correctly? #2946

• Node.js Version:
  v12.18.3

• OS:
  macOS 10.15.6

• Scope (install, code, runtime, meta, other?):
  ???

• Module (and version) (if relevant):
  ???

New here, and not quite sure the answers to some of the above.

Stepping through my code with node inspect as documented here: https://nodejs.org/docs/latest-v12.x/api/debugger.html

One of the options is:
• watch(expr): Add expression to watch list

Ok, I'm stepping through my code. I'm in the middle of a function called by a constructor function, instantiating/creating an object in a class. There's a bunch of let <variable> = <value> statements. If I go into repl and ask it to tell me the values of those variables (eg. I have one variable di for argument's sake) it reports them correctly. But (outside of repl again) I do watch(di) and it says Uncaught ReferenceError: di is not defined.

I can't imaging this is a bug, or it would have been found and fixed by others long before I came along. Am I using this incorrectly? How do I add a variable or expression to the watch list without getting that not defined error?

I'd appreciate any help. Thanks!