I'm trying to do what is described here.

That is, execute the following:

BEGIN;
DROP ROLE grafana;
ROLLBACK;

and get the:

list of permissions it can find that are granted to the role.

I can't seem to do this. I see no output and the Messages after executing don't help:

The docs don't give any indication that this actually does what @user:176905 said in the linked answer.