PG Bug reporting form <noreply(at)postgresql(dot)org> writes:
> In the upgrade process with pg_upgrade ( as user postgres) following error
> occured:
> pg_restore: Error: could not execute query: ERROR: Language »plperlu« does
> not exist
> The statement was: CREATE OR REPLACE PROCEDURAL LANGUAGE "plperlu";
It looks like you neglected to install the plperlu package
(it's probably named something like postgresql-plperl).
regards, tom lane