It worked! Different problem now... I'm trying to follow the steps outlined here: https://github.com/pulumi/pulumi/issues/1662#issuecomment-483718863. However I cannot seem to get Pulumi to "adopt" the CF stacks. It wants to discard the Stacks adopted with

aws.cloudformation.Stack.get

and create new ones. Is there a way to see why Pulumi wants to do that?