:pointer argument is not a valid pointer

[guncha]

This very simple snippet doesn't seem to work for me and I don't know why:

mod = RLTK::CG::Module.new("Hello")
mod.globals.add(RLTK::CG::Int32Type, "hello")

Stacktrace:

ArgumentError: :pointer argument is not a valid pointer
from /Users/gunca/.rvm/gems/ruby-2.1.5/gems/rltk-3.0.0/lib/rltk/cg/module.rb:391:in `add_global'

Running against LLVM-3.4 from Homebrew.