Why doesn't my bundle build for Mac OS X using Xcode 4.5?

I am using a static library (.a) and writing a wrapper for it, as specified here. I have made sure that all my build settings say 32-bit, as I've read multiple places that 64-bit causes problems. I have created a workspace that includes the library itself and separately a Cocoa Bundle, just like this post suggested. I'm new to Mac programming so I'm sure I'm overlooking something obvious. I do wish there was more in the Unity documentation other than build a bundle.