[gentoo-user] compile error / missing libraries?

[Sevak Avakians]

Hello,

I'm trying to compile a program called "breve".  It lists the following as required libraries:
  OpenGL
  GLUT
  ODE
  expat
  zlib
  libpthread
  libdl

I have already emerged opengl, glut, ode, and expat.  zlib is already on my system, too.  I cannot find libpthread or libdl in portage, although the instructions state the libdl is probably already installed on most systems.  Searching for a file named libdl turns up nothing.

When I run make on the breve folder, it gives me the following:

...alot of other stuff that compiled correctly followed by this:
make[2]: Entering directory `/home/sevak/breve_source/breve_source/graph'
gcc -O4 -DHAVE_CONFIG_H -c graph.c  -I../include/breve
gcc -O4 -DHAVE_CONFIG_H -c draw.c  -I../include/breve
ar crv libbrgraph.a graph.o draw.o
a - graph.o
a - draw.o
cp *.h ../include/breve
cp libbrgraph.a ../lib
ranlib libbrgraph.a
ranlib ../lib/libbrgraph.a
gcc -O4 -DHAVE_CONFIG_H -o graphTest graphTest.c -I../include/breve -L. -lbrgraph -L../lib -L. -lbrutil -lz -Xlinker -Bdynamic -L/usr/X11R6/lib -lglut -lGL -lGLU -lXmu -lXt -lSM -lICE -lX11 -lXi -lXext -DHAVE_CONFIG_H
../lib/libbrutil.a(text.o)(.text+0x15b): In function `slUtilReadFile':
: undefined reference to `errno'
collect2: ld returned 1 exit status
make[2]: *** [graphTest] Error 1
make[2]: Leaving directory `/home/sevak/breve_source/breve_source/graph'
make[1]: *** [all] Error 2
make[1]: Leaving directory `/home/sevak/breve_source/breve_source'
make: *** [optimize] Error 2

Looks like the problem is a "graph" or graphic related problem?  I would imagine it has something to do with opengl or glut, but both are installed on my system.  So I assume it may have something to do with the other 2 libraries that I cannot find.

Am I able (meaning without crippling my system) to use any libpthread or libdl?  If so, what folder should I install this into?  I run gentoo-2.4.

Thanks in advance!
Sevak