Freebsd 6.2 Ports Install Needs XORG_UPGRADE Environment Variable

On a FreeBSD 6.2 machine, installing a port having an xorg dependency returned with this error:

...
===> Verifying install for /usr/local/libdata/xorg/libraries in /usr/ports/x11/xorg-libraries
Read /usr/ports/UPDATING for the procedure to upgrade or install xorg 7.2.
*** Error code 1
...

At least 2 workarounds are available.
1.) Setting an environment variable XOR_UPGRADE will bypass the xorg upgrade message:

% make deinstall clean
% set XORG_UPGRADE=yes
% make install clean

2.) Pass WITHOUT_X11 argument to make:
% make -DWITHOUT_X11 install clean

Works for me! ;)