can't build linkparser on snow leopard

I'm trying to build LinkParser in Ruby.

I have RVM Ruby 1.9.2, initially the installer failed to build LinkParser because link-grammar wasn't present, but once I installed it with sudo port install link-grammar, the build error changed to this:

checking for pkg-config..开发者_JS百科. yes
MacOS X build: fixing architecture flags:
  using the value in ARCHFLAGS environment variable ("-arch x86_64").
checking for dictionary_create() in -llink-grammar... yes
checking for link-grammar/link-includes.h... no
*** extconf.rb failed ***

It says the link-includes.h file is missing. Are there any other packages I'm missing that need to be present in order to get this installed?

---

the macports version is too old, It requires at least version 4.7.0 of link-grammar, so I just compiled it from source and it worked.