example.nix

with import <nixpkgs> {};

let
  openscenegraph' = openscenegraph.overrideAttrs (old: {
    name = "OpenSceneGraph-3.4.0";
    src = /root/OpenSceneGraph-3.4.0.zip;
  });
in stdenv.mkDerivation {
  name = "example";
  buildInputs = [ cmake mesa openscenegraph' pkgconfig ];
}