"Well defined subprograms" is key here -- in a mutable language like Go, goroutines are not well-defined subprograms, so exceptions are tricky to use correctly.

"Well defined subprograms" is key here -- in a mutable language like Go, goroutines are not well-defined subprograms, so exceptions are tricky to use correctly. Edit: I should clarify that's just speculation/personal opinion on my part. I'm not sure what djb had in mind.