Code:
# cd /usr/ports/editor/emacs
# make -DWITHOUT_X11 install clean
or
Code:
# make WITHOUT_X11=set install clean
If the WITHOUT_X11 make variable is set (doesn't matter what it is set to), then the port will not build with X11 support.
Adding WITHOUT_X11=whatever to /etc/make.conf will tell all ports in the tree to build without X11 support.