Odd warning from pg_dump

In connection with a question on -general, I tried this:

$ pg_dump -n '*' regression >regression.dump
pg_dump: WARNING: typtype of data type "any" appears to be invalid
pg_dump: WARNING: typtype of data type "anyarray" appears to be invalid
pg_dump: WARNING: typtype of data type "anyelement" appears to be invalid
pg_dump: WARNING: typtype of data type "anyenum" appears to be invalid
pg_dump: WARNING: typtype of data type "anynonarray" appears to be invalid
pg_dump: WARNING: typtype of data type "anyrange" appears to be invalid
pg_dump: WARNING: typtype of data type "cstring" appears to be invalid
pg_dump: WARNING: typtype of data type "event_trigger" appears to be invalid
pg_dump: WARNING: typtype of data type "fdw_handler" appears to be invalid
pg_dump: WARNING: typtype of data type "index_am_handler" appears to be invalid
pg_dump: WARNING: typtype of data type "internal" appears to be invalid
pg_dump: WARNING: typtype of data type "language_handler" appears to be invalid
pg_dump: WARNING: typtype of data type "opaque" appears to be invalid
pg_dump: WARNING: typtype of data type "pg_ddl_command" appears to be invalid
pg_dump: WARNING: typtype of data type "record" appears to be invalid
pg_dump: WARNING: typtype of data type "trigger" appears to be invalid
pg_dump: WARNING: typtype of data type "tsm_handler" appears to be invalid
pg_dump: WARNING: typtype of data type "void" appears to be invalid
$

The datatypes being complained of are evidently all the pseudo-types.
I haven't looked into the code to figure out why this happens.
The dump is produced anyway, so it's only a cosmetic issue, but seems
probably worth fixing.
        regards, tom lane