We want to enforce access policies to reviews (differential) and those are based on the access policy of the repository (diffusion). However, since it's possible to create reviews without a repository, those review would be wild open to everyone.
How can we prevent the creation of reviews that don't have a repository?
Use Herald to create a rule that prevents creation of reviews without repository.
Create a Herald rule like this:
Global rule that acts on Differential Diffs:
[ Repository ] [ does not exist ]
[ Block diff with message ] [ "Diffs must have a repository." ]
You may want to make the message, e.g., have the URL for a wiki page because next steps may not be clear if users hit this after running arc without understanding how to configure things locally.