configure: error: in `/wrkdirs/usr/ports/devel/libgtop/work/libgtop-2.28.4':
configure: error: The pkg-config script could not be found or is too old.  Make sure it
is in your PATH or set the PKG_CONFIG environment variable to the full
path to pkg-config.

Alternatively, you may set the environment variables GLIB_CFLAGS
and GLIB_LIBS to avoid the need to call pkg-config.
See the pkg-config man page for more details.

To get pkg-config, see <http://pkg-config.freedesktop.org/>.
See `config.log' for more details
===>  Script "configure" failed unexpectedly.
Please run the gnomelogalyzer, available from
"http://www.freebsd.org/gnome/gnomelogalyzer.sh", which will diagnose the
problem and suggest a solution. If - and only if - the gnomelogalyzer cannot
solve the problem, report the build failure to the FreeBSD GNOME team at
gnome@FreeBSD.org, and attach (a)
"/wrkdirs/usr/ports/devel/libgtop/work/libgtop-2.28.4/config.log", (b) the
output of the failed make command, and (c) the gnomelogalyzer output. Also,
it might be a good idea to provide an overview of all packages installed on
your system (i.e. an `ls /var/db/pkg`). Put your attachment up on any website,
copy-and-paste into http://freebsd-gnome.pastebin.com, or use send-pr(1) with
the attachment. Try to avoid sending any attachments to the mailing list
(gnome@FreeBSD.org), because attachments sent to FreeBSD mailing lists are
usually discarded by the mailing list software.
*** [do-configure] Error code 1