From: Ralf Mueller <ralf.mueller@...>
Date: 2011-04-14T17:13:35+09:00
Subject: Re: problem with swig & ruby

37 min of waiting is not that long....get yourself a coffee as a pacifier
here is my hint:

to get the right value for CPPFLAGS, call this script:

require 'mkmf'
if RUBY_VERSION[0,3] == '1.8'
   puts "-I#{Config::expand(CONFIG['rubyhdrdir'])}"
else
   puts "-I#{Config::expand(CONFIG['rubyhdrdir'])} 
-I#{Config::expand(CONFIG['rubyhdrdir'])}/#{Config::expand(CONFIG['arch'])}"
end


On my system, its outpout is
-I/usr/include/ruby-1.9.1 -I/usr/include/ruby-1.9.1/x86_64-linux

Ruby uses two config.h files, one for platform independent and one for platform dependent settings.

hth
ralf