Ok, that explains this code in the main:

(defn -main [& args]
  (cond
    (some #{"migrate" "rollback"} args)
    (do
      (mount/start #'toyappt.config/env)
      (migrations/migrate args (select-keys env [:database-url]))
      (System/exit 0))
    :else
    (start-app args)))

Add migrate to the end of my Procfile?

web: java $JVM_OPTS -cp target/uberjar/toyapp.jar clojure.main -m toyapp.core migrate

AH! Heroku is a read only file system, so you cannot use sqlite or in my case H2.

but hey, I learned a lot! Switching over to postgres!

@olleromo Thank you so much for more detailed doc!!

😊

is there somewhere a run-through for setting up a new luminus project with postgreSQL?

oh... I just found a chapter on the matter in the number one luminus book... (should have looked at the index before asking...)