@niwinz: I mentioned this error before (https://clojurians-log.clojureverse.org/funcool/2016-05-27.html) but no resolution came about and I am running into it again so I thought I would create a minimal, reproducible example of the problem so we can fix this. I have opened an issue (https://github.com/funcool/promesa/issues/23) in promesa as I believe the problem exists somewhere in its dependency tree. I will try to investigate a bit more to resolve this problem.