extconf.rb generates a MAKE file in the same folder as itself.
However, for my project I compile on Windows and OSX. I would like to
make it so that when I compile on one platform all the files generated
is placed in a folder for that platform. So that under windows
everything is outputted in an folder named “win” and under OSX a folder
named “osx”.
I really cannot find how you configure a custom output folder.