Static library gives error on iOS simulator and works on iOS device

Question

Currently I'm working on a iOS application (iOS 6), In which I need to implement a static library.

I successfully implemented the Static library using this tutorial. And I successfully added the static library to other project and Installed the app to iPhone !. It's working successfully.

But my issue is when I tried to run it on my simulator some errors are coming:

 "_OBJC_CLASS_$_MMPAlert", referenced from:
      objc-class-ref in ViewController.o
ld: symbol(s) not found for architecture i386
clang: error: linker command failed with exit code 1 (use -v to see invocation)

I added the target architecture like:

I searched a lot but couldn't find a solution, why my library is working on device and giving error on simulator.

Please help me, thanks in advance

Answer 1

You have propably built your library for the device architecture only. The iOS Simulator is not an emulator, meaning the code needs to be able to run on your Mac's architecture, which is obviously different from your device's architecture.

As a library is precompiled (for a specific architecture), the code it consists of doesn't get compiled again for your current target once you use it in your project. This is why you need to build your library for both architectures in the first place.

This SO Answer explains how to bundle two library builds into one handy "fat file".