So, the investigation continued a bit more. Turns out my original fix was papering over a deeper problem. We were depending on jinx which in turn has a dependency on clojurescript which contains itโs own version of the clojure.tools.reader ns which I suppose is somehow incompatible with the one expected by rewrite-clj.
Ah, thanks for the follow-up @cddr! We do override https://clojure.atlassian.net/browse/TRDR-65. I guess the fix is to force the current version of tools reader?
We just excluded clojurescript when depending on jinx which seemed to do the trick