Re: BUG #16672: Postgres user passwords are corrupted during migration

PG Bug reporting form <noreply@postgresql.org> writes:
> The postgres user password is corrupted when migrating from Postgresql 12.4
> to Postgresql 13.

I tried to verify that claim, without success: AFAICS, dump/reload will
correctly propagate the password to the new server, in either md5 or
SCRAM format.

You have not shown very much supporting detail, but I wonder whether
the password is hashed in md5 format and the v13 server's pg_hba.conf
is set to only allow SCRAM passwords.  The report sent to the client
intentionally just says "password authentication failed", but you
could look in the postmaster log to see what it says about the failure.
Also, look in pg_authid (of either server), or in the dump file, to see
whether the rolpassword value starts with "md5" or "SCRAM-SHA-256".

            regards, tom lane