pg_upgrade 9.6->9.6: column "amtype" does not exist

Hi,

I'm not sure this is a bug, but before it bites back too late, I'm
reporting it now.

On pg_upgrading my catversion 201603111 9.6 cluster to 201603301, I
got the following error:

-----------------------------------------------------------------
pg_upgrade run on Fri Apr 1 22:50:07 2016
-----------------------------------------------------------------

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 reg* system OID user data types ok
Checking for contrib/isn with bigint-passing mismatch ok
Creating dump of global objects ok
Creating dump of database schemas

*failure*
Consult the last few lines of "pg_upgrade_dump_13007.log" for
the probable cause of the failure.

command: "/usr/lib/postgresql/9.6/bin/pg_dump" --host "/var/log/postgresql/pg_upgradecluster-9.6-9.6-main.lLkW" --port 5433 --username "postgres" --schema-only --quote-all-identifiers --binary-upgrade --format=custom --file="pg_upgrade_dump_13007.custom" "postgres" >> "pg_upgrade_dump_13007.log" 2>&1
pg_dump: [Archivierer (DB)] Anfrage fehlgeschlagen: FEHLER: Spalte „amtype“ existiert nicht
ZEILE 1: SELECT tableoid, oid, amname, amtype, amhandler::pg_catalog....
^
TIP: Perhaps you meant to reference the column "pg_am.amname".
pg_dump: [Archivierer (DB)] Anfrage war: SELECT tableoid, oid, amname, amtype, amhandler::pg_catalog.regproc AS amhandler FROM pg_am

'FEHLER...' translates to 'ERROR: Column "amtype" does not exist'.

Christoph