=> GUIlib-1.1.1.tar.gz doesn't seem to exist in /usr/ports/distfiles/.
=> Attempting to fetch from http://www.libsdl.org/projects/GUIlib/src/.
fetch: http://www.libsdl.org/projects/GUIlib/src/GUIlib-1.1.1.tar.gz: Requested Range Not Satisfiable
=> Attempting to fetch from ftp://ftp.FreeBSD.org/pub/FreeBSD/ports/distfiles/.
fetch: ftp://ftp.FreeBSD.org/pub/FreeBSD/ports/distfiles/GUIlib-1.1.1.tar.gz: size mismatch: expected 179035, actual 180324
=> 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/graphics/guilib.
*** Error code 1

Stop in /usr/ports/games/duke3d.
zephram# ls /usr/ports/distfiles/GUIlib-1.1.1.tar.gz
/usr/ports/distfiles/GUIlib-1.1.1.tar.gz
zephram#