[Gmsh] compile with opencascade

[Jon]

Hi, I'm trying to complile gmsh with opencascade
I get as far as ./configure --enable-occ
--with-occ-prefix=/usr/local/opencascade
that all does its thing with no errors. Then I run make and it gives
this:
ake[2]: Leaving directory
`/home/jon/Documents/gmsh-2.3.1/contrib/Netgen/libsrc/opti'
make[2]: Entering directory
`/home/jon/Documents/gmsh-2.3.1/contrib/Netgen/libsrc/interface'
make[2]: Nothing to be done for `default'.
make[2]: Leaving directory
`/home/jon/Documents/gmsh-2.3.1/contrib/Netgen/libsrc/interface'
/usr/bin/ar ruvs ../../lib/libGmshNetgen.a *.o libsrc/*/*.o
ranlib ../../lib/libGmshNetgen.a
make[1]: Leaving directory
`/home/jon/Documents/gmsh-2.3.1/contrib/Netgen'
make[1]: Entering directory
`/home/jon/Documents/gmsh-2.3.1/contrib/MathEval'
make[1]: `../../lib/libGmshMathEval.a' is up to date.
make[1]: Leaving directory
`/home/jon/Documents/gmsh-2.3.1/contrib/MathEval'
g++ -g -O2 -o bin/gmsh -Llib -lGmshFltk -lGmshCommon -lGmshMesh
-lGmshGeo -lGmshPost -lGmshPlugin -lGmshCommon -lGmshGraphics
-lGmshParser -lGmshNumeric -lGmshTreeBrowser -Wl,-Bsymbolic-functions
-lfltk_images -lfltk_gl -lfltk -lGLU -lGL -ljpeg -lpng -lGmshANN
-lGmshChaco -lGmshMetis -lGmshNetgen -lGmshMathEval -lz -lm
/usr/bin/ld: cannot find -lGL
collect2: ld returned 1 exit status
make: *** [link] Error 1
jon at ubuntu:~/Documents/gmsh-2.3.1$ 
those are the last few lines. 
My system is Ubuntu 8.10  with everything to make automake configure and
everything installed correctly 
Any Ideas on what I can do? I really need to import IGES files into
Gmsh.