Upgrading 8.2 to 9.1, Gnome issue

[Hrisikesh sahu]

Hi All,
I followed this following link to upgrade from 8.2 RELEASE to 9.1 RELEASE.
*http://www.freebsd.org/releases/9.0R/installation.html*

After
 Code:

# freebsd-update fetch
# freebsd-update install

Now the freebsd-update(8) <http://man.freebsd.org/freebsd-update/8> utility
can fetch bits belonging to 9.1-RELEASE. During this process
freebsd-update(8) <http://man.freebsd.org/freebsd-update/8> will ask for
help in merging configuration files.
 Code:

# freebsd-update upgrade -r 9.1-RELEASE

# freebsd-update install

The system must now be rebooted with the newly installed kernel before the
non-kernel components are updated.
 Code:

# shutdown -r now

I followed the following command to upgrade Ports -

# portupgrade -fr gnome-session

But I am facing a problem "shared object libz.so.5 not found freebsd"

I did all these steps to upgrade the ports
 Code:

#pkgdb -fF
# rm /var/db/pkg/pkgdb.db
# portupgrade -arRn

but i am facing a issue with -
 Code:

/usr/local/sbin/portupgrade:1473:in `get_pkgname': Makefile broken
(MakefileBrokenError)

Please help me how to come out from this Makefile broken and "shared object
libz.so.5 not found freebsd".

Regards
Hrisikesh