best way to get distfiles added to ports.tgz during make release

[Aryeh Friedman]

I have made a custom install USB drive from R/cdrom/dvd1 and pkg_add works
fine for everything but xorg/nvidia-driver so part of the post install
script I made is "portmaster xorg/nvidia-driver" the only problem is it then
needs to fetch the distfiles (the target install machine{s) will not have
nic's attached)... so my questoin is whats the best way to make it so when
sysinstall unpacks ./8.2-NHK_KIOSK/ports/ports.tgz that the distfiles are
also unpacked?