I don’t have enough karma on SO to comment there: it looks like you’ve bumped into the root cause of this before, assuming you’re the same Khalid Jebbari:
https://dev.clojure.org/jira/browse/CLJ-2246?focusedCommentId=47934#comment-47934
I’ve provided a work-around there. Hopefully we can get this a resolution to this issue, as I’m sure others will get bitten by this.
I’m not sure what changed: it could be test.check rather than spec.alpha. I didn’t go too far down the rabbit hole of looking for the regression (if there has been one) before just trying to fix it.