I just had a bit of trouble understanding why rake-compiler was installing the C extension to a different location than rubygems did when I installed the gem.
Turns out that my call to create_makefile had a different value than when I created the ExtensionTask. If these values are not the same by default then things go screwy.
I think this should be reflected in the documentation somewhere or perhaps rake-compiler can be changed to use the same value as create_makefile without the value needing to be specified in two different places.
@ferrous26 patches are welcome. I'm not a native english speaker so if you can write that down, better.
As for automatic detection, I'm not fond for that, too much magic is bad for your health 😄
Add note that ExtensionTask param should match create_makefile