Installing ddd on LilyBuntu

[Phil Holmes]

I thought it'd be interesting to install the ddd graphical debugger on my 
LilyBuntu instance.  I downloaded it OK, but when I run ./configure I get:

"configure: error: The X toolkit library '-lXt' could not be found."

I can't find how to fix this with a Google search.  Does anyone who 
runs/created LB know whether there is an X toolkit library installed?  If 
so, what/where?  If not, is it possible to install one?

--
Phil Holmes
Bug Squad