pg_upgrade from Postgresql-12 to Postgresql-13 fails with "Creating dump of database schemas postgres *failure*"

Hi I hope I send this to the right mailing list and able to get some help.

I was trying to perform `pg_upgrade` from Postgresql-12 to Postgresql-13
(after being advised that upgrading from Postgresql-12 to Postgresql-14 is
biting off much more than I could chew... ).

The `pg_upgrade --check` went through OK. But the actual `pg_upgrade`
always get error at the step of *Creating dump of database schemas* for
`postgres` database.

```

/usr/lib/postgresql/13/bin/pg_upgrade
--old-datadir=/bnas/pgdata/postgresql/12/main
--new-datadir=/bnas/pgdata/postgresql/13/main
--old-bindir=/usr/lib/postgresql/12/bin
--new-bindir=/usr/lib/postgresql/13/bin --old-options '-c
config_file=/etc/postgresql/12/main/postgresql.conf' --new-options '-c
config_file=/etc/postgresql/13/main/postgresql.conf' --check

Performing Consistency Checks

-----------------------------

Checking cluster versions ok

Checking database user is the install user ok

Checking database connection settings ok

Checking for prepared transactions ok

Checking for system-defined composite types in user tables ok

Checking for reg* data types in user tables ok

Checking for contrib/isn with bigint-passing mismatch ok

Checking for presence of required libraries ok

Checking database user is the install user ok

Checking for prepared transactions ok

Checking for new cluster tablespace directories ok

*Clusters are compatible*

postgres(at)ual:~$ /usr/lib/postgresql/13/bin/pg_upgrade
--old-datadir=/bnas/pgdata/postgresql/12/main
--new-datadir=/bnas/pgdata/postgresql/13/main
--old-bindir=/usr/lib/postgresql/12/bin
--new-bindir=/usr/lib/postgresql/13/bin --old-options '-c
config_file=/etc/postgresql/12/main/postgresql.conf' --new-options '-c
config_file=/etc/postgresql/13/main/postgresql.conf'

Performing Consistency Checks

-----------------------------

Checking cluster versions ok

Checking database user is the install user ok

Checking database connection settings ok

Checking for prepared transactions ok

Checking for system-defined composite types in user tables ok

Checking for reg* data types in user tables ok

Checking for contrib/isn with bigint-passing mismatch ok

Creating dump of global objects ok

Creating dump of database schemas

postgres

*failure*

Consult the last few lines of "pg_upgrade_dump_13427.log" for

the probable cause of the failure.

Failure, exiting

```

Here are the logs: pg_upgrade_server.log <https://pastebin.com/ePDpmheE>,
pg_upgrade_dump_13427.log <https://pastebin.com/YTsU4hYh> and
tail_postgresql-12-2022-02-16_190344.log <https://pastebin.com/KP8ePVct>.

Additional information:

1.

An observation on `pg_upgrade --check`. I could not run actual
`pg_upgrade` directly after the `--check` operation as I will always get
some `server not shut down properly` error.
2.

I have PostGIS and a couple other audit/monitoring extensions installed
on Postgresql-12. I have installed the similar Ubuntu PostGIS packages for
Postgresql-13. Do I need to run `CREATE EXTENSIONS xxx` before performing
the `pg_upgrade`?

Have been stuck with this for over a week now, and sincerely hope someone
could help me. TIA.

chow