I\'ve just upgraded my app to run on the new iPhone5 simulator, however when I try to build it for my iPhone 4S device, I get this Apple Mach-O Liner error.
Try this:
This article copy an armv7 lib code as an armv7s and build into the original lib. so xcode will see that lib has an armv7s code/arch
http://www.galloway.me.uk/2012/09/hacking-up-an-armv7s-library/