When symbolicating iOS crashes, scripts use iOS debug symbols that are stored in ~/Library/Developer/Xcode/iOS DeviceSupport. I've got a crash from iOS 7.1.2 (11D257) where all the lines in the module list but the actual executable have the armv7s architecture, like this:
0x30c8d000 - 0x30e77fff Foundation armv7s <52121842f9863ab49b775758dd05db0b> /System/Library/Frameworks/Foundation.framework/Foundation
I've got this very version of iOS under DeviceSupport, however, the system stackpoints fail to symbolicate; the script claims that none of the iOS files has the armv7s slice. Indeed, if I run
lipo -info '~/Library/Developer/Xcode/iOS DeviceSupport/7.1.2 (11D257)/Symbols/System/Library/Frameworks/Foundation.framework/Foundation'
it says that only armv7 is present.
I've pulled the symbols from an iPhone 4; its CPU doesn't support armv7s. If you have an armv7s-capable device (iPhone 5+, iPad 3+) with iOS 7.1.2, can you please run the same command and confirm that the version of Foundation you have contains the armv7s slice?
You get armv7s iOS system symbols from devices with armv7s or arm64 CPU. The iPhone 4 has a armv7 CPU, so it obviously can't provide you with armv7s symbols.