[sugar] How to add a library to the build tree?

[Don Hopkins]

I'm trying to add the poppler library to the build, and make another 
library that's a python extension for using it.
Do I have to hack jhbuild to integrate poppler into the build? (I'm not 
ready to check it in yet, just making it in a sandbox for now.)
I tried just going to the poppler directory and going "./configure 
--prefix=.../sugar-jhbuild/build", and that made it compile into the 
right place, but it was getting the system libraries instead of the ones 
in the build directory (like cairo, etc).
Do I have to configure each one of the libraries it uses to point to the 
the right directory? Or is there a way to do that en mass? Or a way to 
get sugar-jhbuild to do that for me?
Thanks for the help!

    -Don