How to weaken strongly linked symbols in a mach-o static library?

Question

Our app supports iOS5 however one of our 3rd party static libraries has started strongly linking against iOS6 symbols in UIKit. I'd like to change this linkage to weak and disable the library on iOS5 (assuming the library doesn't use the symbols in load).

I'm looking for something like what I imagine objcopy --weaken-symbol from linux does, so does anyone know of any likely tools or will this involve learning the mach-o format?

Answer 1

I'm none the wiser on mach-o, but I realised that static libraries can't actually decide on how they link against my frameworks. Only I can do that.

So I went into Target > Build Phases > Link Binary With Libraries and set UIKit to Optional. Now the app launches on iOS5 and I can simply (I think!) not call the offending library.

I'm only slightly disappointed I didn't get to write a re-linking tool