Help with adding header files for 'mkmf' - new to Swig/mkmf


I’m trying to extend a simple function from a large C++ API library
for Ruby (OpenAccess). Ultimately I’d like to add functionality over
time; however, I want to get a simple test case up and running as a
proof-of-concept. I believe the problem is properly pointing to the
large C++ library. Let me begin with the problem seen (after using
Swig and extconf.rb):

irb(main):001:0> require ‘libtest’
LoadError: ./ undefined symbol:
_ZNK12OpenAccess_46oaFile6existsEv - ./
from ./
from (irb):1

In my libtest.cpp file I have:

#include “oaDesignDB.h”

And in my extconf.rb file:

require ‘mkmf’
$libs = append_library($libs, “supc++”)

This does not seem to add the path to the “-I” option in the make


even though the header is found.

find_header(‘oaDesignDB.h’, ‘/path/to/the/header’)

And this does not work also even though $INCFLAGS has a value before

as “-I$(topdir)” and with the added path afterwards… it just

doesn’t get

into the make file for some reason

$INCFLAGS += " -I#{path}"