gosu install

[jayso...@gmail.com]

I am very much a novice.  Helping my son with make a game as a school project.  I loaded the Xcode off of install disk.  I have "Xcode Tools.mpkg" that I installed. When I did the gosu library install I got this:

Jayson-Docks-iMac:~ jaysondock$ sudo gem install gosu

Password:

Building native extensions.  This could take a while...

ERROR:  Error installing gosu:

ERROR: Failed to build gem native extension.

/System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/bin/ruby extconf.rb

mkmf.rb can't find header files for ruby at /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib/ruby/ruby.h

The Gosu gem requires some libraries to be installed system-wide.

See the following site for a list:

https://github.com/jlnr/gosu/wiki/Getting-Started-on-Linux

I looked at the web site above, but can not figure out what I am missing or what the problem is.

Thanks!

Jayson