It looks like sdl-config needs to be located in bin/ not in lib/. It worked for me after putting it in $DEVKITPPC/bin. The paths in sdl-config seems to be hard-coded "-L/c/dev/apps/devkitPro/libogc/lib/wii" etc - should be dependent on location of libogc and devkitpro.
:Right, sdl-config is just a shell script for handling includes, flags, etc more easily, the important thing is just to have sdl-config in your PATH
, ( on windows, you can even put it in system32) note that you can use the same sdl- config for the PC and Wii with two msys ( one for 'PC', one for Devkitpro) and mounting /mingw in each fstab to the path of your libs ( - ex : msys PC fstab c:/MinGW /mingw msys for devkitpro wii : c:/devkitpro/devkitPPC/powerpc-gekko /mingw
then only use /mingw into the sdl-config