I've tried to crack this one as well. After learning that RubyGems will build extensions using configure-make-install in addition to extconf.rb, I have a branch of ruby-llvm that uses the autotools to build and manage a shared library, but unfortunately haven't released it yet because of incompatibilities between autoconf versions on Mac and Ubuntu. 

You can see my approach at https://github.com/jvoorhis/ruby-llvm/tree/support-lib. If anyone is an autotools pro, or has a better idea, please help! :)

Jeremy 


On Sunday, October 23, 2011 at 2:49 AM, mixtli wrote:

>  I want to package up my c source with my gem, and call it from ffi.
> How can I tell ffi to use a library packaged with the gem instead of
> looking in the system libraries?