I keep on getting the above error whenever I run the following command via a postgres user.
/usr/lib/postgresql/9.3/bin/pg_upgrade \\ -b /usr/lib/postgres
Make sure that you run this command from a directory that is writable by the postgres user, like /tmp or /var/lib/postgresql:
postgres
/tmp
/var/lib/postgresql
$ cd /tmp $ usr/lib/postgresql/9.3/bin/pg_upgrade ...