After fresh cvsup of ports tree, attempts to portupgrade Gnome ports to latest in ports tree fail
due to unfetchable libnotify-0.4.3.tar.gz dependency. See below for example with gnome-applets:

# portupgrade -R gnome-applets-2.16.1_2
--->  Upgrading 'libnotify-0.4.2_2' to 'libnotify-0.4.3' (devel/libnotify)
--->  Building '/usr/ports/devel/libnotify'
===>  Cleaning for libtool-1.5.22_2
===>  Cleaning for gmake-3.81_1
===>  Cleaning for intltool-0.35.0
===>  Cleaning for pkg-config-0.21
===>  Cleaning for dbus-glib-0.72
===>  Cleaning for popt-1.7_1
===>  Cleaning for atk-1.12.3
===>  Cleaning for glib-2.12.4
===>  Cleaning for gtk-2.10.6_2
===>  Cleaning for pango-1.14.7
===>  Cleaning for gettext-0.14.5_2
===>  Cleaning for perl-5.8.8
===>  Cleaning for p5-XML-Parser-2.34_2
===>  Cleaning for libiconv-1.9.2_2
===>  Cleaning for dbus-1.0.0
===>  Cleaning for png-1.2.12_1
===>  Cleaning for tiff-3.8.2
===>  Cleaning for jpeg-6b_4
===>  Cleaning for xorg-libraries-6.9.0
===>  Cleaning for shared-mime-info-0.19
===>  Cleaning for hicolor-icon-theme-0.9_2
===>  Cleaning for freetype2-2.2.1_1
===>  Cleaning for cairo-1.2.6
===>  Cleaning for libXft-2.1.7_1
===>  Cleaning for xorg-fonts-truetype-6.9.0
===>  Cleaning for xorg-fonts-encodings-6.9.0_1
===>  Cleaning for expat-2.0.0_1
===>  Cleaning for libxml2-2.6.26
===>  Cleaning for gnome_subr-1.0
===>  Cleaning for imake-6.9.0
===>  Cleaning for libdrm-2.0.2
===>  Cleaning for fontconfig-2.3.2_6,1
===>  Cleaning for glitz-0.5.6
===>  Cleaning for xorg-clients-6.9.0_3
===>  Cleaning for bitstream-vera-1.10_2
===>  Cleaning for xterm-222
===>  Cleaning for libnotify-0.4.3
===>  Vulnerability check disabled, database not found
=> libnotify-0.4.3.tar.gz doesn't seem to exist in /usr/ports/distfiles/.
=> Attempting to fetch from http://www.galago-project.org/files/releases/source/libnotify/.
fetch: transfer timed out
=> Attempting to fetch from ftp://ftp.FreeBSD.org/pub/FreeBSD/ports/distfiles/.
fetch: ftp://ftp.FreeBSD.org/pub/FreeBSD/ports/distfiles/libnotify-0.4.3.tar.gz: File unavailable
(e.g., file not found, no access)
=> Couldn't fetch it - please try to retrieve this
=> port manually into /usr/ports/distfiles/ and try again.
*** Error code 1

Stop in /usr/ports/devel/libnotify.
** Command failed [exit code 1]: /usr/bin/script -qa /tmp/portupgrade.66426.16 env PORT_UPGRADE=yes
make
** Fix the problem and try again.
--->  Skipping 'x11/gnome-applets' (gnome-applets-2.16.1_2) because a requisite package
'libnotify-0.4.2_2' (devel/libnotify) failed (specify -k to force)
** Listing the failed packages (*:skipped / !:failed)
        ! devel/libnotify (libnotify-0.4.2_2)   (fetch error)
        * x11/gnome-applets (gnome-applets-2.16.1_2)
--->  Packages processed: 0 done, 108 ignored, 1 skipped and 1 failed
#

Fix: 

I imagine, making the libnotify-0.4.3.tar.gz file available, would do the trick.
How-To-Repeat: Update ports tree to today's latest
Attempt to portupgrade Gnome related ports to latest in ports tree