ok, I'm a joker n00b. What is the idiomatic way to throw an exception (aka what is the exception type?)

nm, found it: ex-info

Joker v0.14.0 is released: https://github.com/candid82/joker/releases/tag/v0.14.0

it now supports concurrency (core.async style) with goroutines and channels. See https://candid82.github.io/joker/joker.core.html#go for details. Concurrency primitives are currently limited to go, chan, <! and >!.

Excellent! I want to try out ns-sources as well.