After failing to build Xfce4, I tried a fresh install of DF-i386-gui-3.0.2 again; followed by a pkg_rolling-replace -u before any attempt at building Xfce4.
This failed miserably.
I tried a fresh install of DF-i386-gui-3.0.2 followed by:
pkg_chk -g
pkg_chk -r
pkg_chk -as
This, also, turned into a mess of missing packages or outdated packages (
and a missing checksum!).