How do I build an app and framework on OS X 10.6 that can run on 10.5?

Question

Here's my situation: I have the source code for a third-party framework that I want to include in my project. I'm developing on 10.6 but I want to support 10.5, so I have the base SDK and the deployment target set to 10.5.

I can build the framework and the application, and the app runs inside Xcode and on the machine. However, it fails on a 10.5.8 and crashes. The crash report says

Unknown required load command 0x80000022

I have also tried building the framework on the 10.5.8 machine, setting the architecture to '32/64-bit Universal'. Moving this framework to the 10.6 machine and attempting to build the app works, but the app fails to run, throwing multiple errors of:

-[NSCFArray matchAndAssemble:]: unrecognized selector sent to instance 0x3503c0

Has anyone seen this before? Do you know of a fix or workaround? It can't be an uncommon situation.

Answer 1

Answer for the first error: unable to read unknown load command 0x80000022 - Stack Overflow, and it might have a bearing on the second error. What version Xcode and SDK are you using?

Answer 2

The loader command being flagged is the loader command for a compressed binary which is a binary type supported only on 10.6.

matchAndAssemble: is not a (documented) method of NSArray/NSMutableArray. It is, however, a method of the PKParser kit. Is that the framework you are trying to build?

Anyhow, something in your project is being built only for 10.6 and it's probably that framework. Check the build settings for all of your targets, and any targets of any sub projects and do an otool -l on any third party frameworks to look for the 22 load command.