Right, thanks for that note :)

provideSome is an option, however it requires you to provide a method to construct the new environment by hand. If used often, it could be quite tedious to write those :)

But then, if the number of env-managed dependencies is small, it could be just a couple of functions … e.g. Clock with Connection => Clock and similar. What would further constraint the number of these functions is the env you actually use when working with the database.