just FYI, that stackoverflow problem seems to be caused by :parallel-build true, maybe I messed up my config and parallel builds race somehow

I was finally able to reproduce it on my dev machine and disabling parallel-build reproducibly fixed the issue (with no other changes)

ah, scratch that, it is back again even without parallel-build

Hmm. I wonder if this recent Clojure commit is portable to ClojureScript. (Looks like a lot of it is, but I wonder about some of the things having the new protocol being extended to it near the bottom of that commit.) https://github.com/clojure/clojure/commit/93841c0dbf9db2f358474408d5e21530f49ef8b3

Stepping back a little, it looks like this provides a way to, say, turn an Atom instance into data.

I'll put together a patch, mostly as an experiment to see what it means.

^ https://dev.clojure.org/jira/browse/CLJS-2929