iOS App crashing before entering main() with Xcode 4.2 & iOS 5

Question

Background

After upgrading xcode4.1/ios4 to xcode4.2/ios5 I am experiencing crashes while the App is loading and before it even enters main().

Answer 1

You can apply the linker flag conditionally to iOS SDKs but not the iPhone Simulator in XCode 4.

Select Other Linker Flags, click Add Build Setting, choose Add Conditional Setting, and apply -weak_library /usr/lib/libSystem.B.dylib just for iOS SDK.

This lets simulator builds still work.