How can I install xorg-clients?

[bob self]

after doing a portupgrade today I've got things messed up. I didn't read 
/usr/ports/UPDATING. I have now un-installed xterm and xorg-clients and 
am now trying to put them back in. I'm trying xorg-clients first but I 
get this error.

xdriinfo.o(.text+0x5b): In function `main':
: undefined reference to `glXGetProcAddress'
*** Error code 1
 


How can I get these ports re-installed?

thanks,
Bob