core.async: faulty rebinding of loop-bindings in go blocks

[Kemar]

There seems to be an issue with the rebinding of loop-bindings using loop/recur in go blocks,
specifically when you are just changing the order of the original bindings in a recur call.

Take this snippet for example:

(require '[clojure.core.async :refer [go timeout]])
(go (loop [a :black, b :white] 
      (println a b)
      (<! (timeout 1000))
      (recur b a)))

Instead of repeatedly printing

:black :white
:white :black
:black :white
:white :black
(...)

 it actually prints

:black :white
:white :white
:white :white
:white :white
(...)

 
Note however, that
 

(require '[clojure.core.async :refer [go timeout]])
(go (loop [a :black, b :white] 
      (println a b)
      (<! (timeout 1000))
      (recur (identity b) (identity a))))

works correctly.

Any ideas as to what's causing this?


Cheers,
Kevin

[Ghadi Shayban]

It's a nasty bug, seems like a local symbol scope issue.  I will take a look at it.  Thanks for the report.

[Ghadi Shayban]

Fixed -- should make it to maven within an hour.

[Kemar]

It appears to be working, awesome!
Thanks!

Cheers,
Kevin