OpenSceneGraph Build Error on Mac OS X 10.6 Snow Leopard

[sam.receive@…]

sam-yeungs-macbook-pro-82:OpenSceneGraph-2.8.2 Sam$ sudo port install openscenegraph
Password:
--->  Computing dependencies for OpenSceneGraph
--->  Building OpenSceneGraph
Error: Target org.macports.build returned: shell command " cd "/opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_release_ports_graphics_OpenSceneGraph/work/OpenSceneGraph-2.8.2" && /usr/bin/make -j2 all " returned error 2
Command output: [ 58%] Built target osgdb_dds
[ 59%] Built target osgdb_tga
[ 59%] Built target osgdb_hdr
[ 59%] Built target osgdb_dot
[ 59%] Built target osgdb_vtf
[ 60%] Built target osgdb_gdal
[ 60%] Built target osgdb_ogr
ld: warning: in /Library/Frameworks//libz.framework/libz, missing required architecture x86_64 in file
Undefined symbols:
  "_inflate", referenced from:
      ive::DataInputStream::uncompress(std::basic_istream<char, std::char_traits<char> >&, std::basic_string<char, std::char_traits<char>, std::allocator<char> >&) constin DataInputStream.cpp.o
  "_inflateEnd", referenced from:
      ive::DataInputStream::uncompress(std::basic_istream<char, std::char_traits<char> >&, std::basic_string<char, std::char_traits<char>, std::allocator<char> >&) constin DataInputStream.cpp.o
      ive::DataInputStream::uncompress(std::basic_istream<char, std::char_traits<char> >&, std::basic_string<char, std::char_traits<char>, std::allocator<char> >&) constin DataInputStream.cpp.o
  "_inflateInit2_", referenced from:
      ive::DataInputStream::uncompress(std::basic_istream<char, std::char_traits<char> >&, std::basic_string<char, std::char_traits<char>, std::allocator<char> >&) constin DataInputStream.cpp.o
  "_deflateInit2_", referenced from:
      ive::DataOutputStream::compress(std::basic_ostream<char, std::char_traits<char> >&, std::basic_string<char, std::char_traits<char>, std::allocator<char> > const&) constin DataOutputStream.cpp.o
  "_deflate", referenced from:
      ive::DataOutputStream::compress(std::basic_ostream<char, std::char_traits<char> >&, std::basic_string<char, std::char_traits<char>, std::allocator<char> > const&) constin DataOutputStream.cpp.o
  "_deflateEnd", referenced from:
      ive::DataOutputStream::compress(std::basic_ostream<char, std::char_traits<char> >&, std::basic_string<char, std::char_traits<char>, std::allocator<char> > const&) constin DataOutputStream.cpp.o
      ive::DataOutputStream::compress(std::basic_ostream<char, std::char_traits<char> >&, std::basic_string<char, std::char_traits<char>, std::allocator<char> > const&) constin DataOutputStream.cpp.o
ld: symbol(s) not found
collect2: ld returned 1 exit status
make[2]: *** [lib/osgPlugins-2.8.2/osgdb_ive.so] Error 1
make[1]: *** [src/osgPlugins/ive/CMakeFiles/osgdb_ive.dir/all] Error 2
make[1]: *** Waiting for unfinished jobs....
[ 60%] Built target osgdb_3dc
make: *** [all] Error 2

Error: Status 1 encountered during processing.

I have tried to install openscenegraph in my 10.6 SL MBP. But it fails to compile.... Please let me know if any further detail is needed. Thank you.