Greg Jandl to SDL I *think* the patch below works correctly: sdl-config gets the -march flag and SDL builds fine. Perhaps there's a better way to get the -march flag into both CFLAGS and SDL_FLAGS w/o dragging along more cruft, but adding it to BASE_CFLAGS seemed the best bet to my eyes.

{
	FilesToRename = {
		"SDLApp_Prefix.pch" = "ÇPROJECTNAMEÈ_Prefix.pch";
	};
	FilesToMacroExpand = (
		"ÇPROJECTNAMEÈ_Prefix.pch",
		"Info.plist",
		"English.lproj/InfoPlist.strings",
		"main.c",
	);
	Description = "This project builds an SDL-based application that uses OpenGL.";
}