{so_name, "geef.so"}.

{port_envs, [
      {"DRV_LDFLAGS", "$DRV_LDFLAGS -lz -lgit2"},

      %% OS X Leopard flags for 64-bit
      {"darwin9.*-64$", "CXXFLAGS", "-m64"},
      {"darwin9.*-64$", "LDFLAGS", "-arch x86_64"},

      %% OS X Snow Leopard flags for 32-bit
      {"darwin10.*-32$", "CXXFLAGS", "-m32"},
      {"darwin10.*-32$", "LDFLAGS", "-arch i386"}
]}.