If you run initdb -A md5, you get an error
initdb: must specify a password for the superuser to enable md5 authentication
In 9.2, when you run something like initdb --auth-local=peer
--auth-host=md5, you still get that error, which I think is a mistake.
The error should only be shown if both authentication choices are
password-like. Hence I propose the attached patch.
