Clojurians Log v2

You're welcome. The shift to assert-key was to enable support other validation systems, while removing the dependency on Clojure spec. You could write your own pre-init-spec method and then use clojure.spec/assert:

(defmethod ig/assert-key :default [k v]
  (s/assert (pre-init-spec k) v))

I was in two minds about whether to remove the dependency or add a temporary deprecated. I think in retrospect it would have been better to add a deprecation and remove it in 0.10.0.

Thanks, I did exactly what you sugested. I backported the pre-init-spec multi-method.