It seems onto-chan retains the head of lazy sequences (at least in Clojure JVM), which can cause memory leaks for large sequences:

;; throws an OOM
(a/onto-chan 
  (a/chan (a/dropping-buffer 1))
  (repeatedly #(byte-array 10000)))

This is in [org.clojure/core.async "0.3.443"] in Clojure JVM 1.8.0

Should I file a bug?

@val_waeselynck there is one already: https://dev.clojure.org/jira/browse/ASYNC-32

seems like it should be fixed in master at least: https://dev.clojure.org/jira/browse/ASYNC-138

@schmee That change has already been merged in my current core-async version (which is the latest)

hmm, then I guess that would be a new issue

@schmee it's weird, seems the patch proposed in ASYNC-32 hasn't been merged

it was supposed to be superseded by the one in ASYNC-138

maybe the best option is to post a comment of that issue with the failing example?

@schmee I guess so, will do, thanks!