how to solve "Needs cairo build with X11 support" when installing ports

When installing some ports (like vim or xfce), it will need "cairo".

Some people might get an error message "Needs cairo build with X11 support", and you will get the answer from google:

# cd /usr/port/graphic/cairo
# make deinstall
# make install clean

howerver, it is useless for me.:(

In fact, you just need to do is:

# make config

enable "X11 (graphics) support" and make it once again!