[CMake] find_library and mac os x SDKs

[Simmons, Aaron]

When compiled on Mac OS X, my project links against the 10.4 SDK.  This SDK is often not installed by default on newer systems (10.6, for example).  I would like to put in a check for whether the SDK is present before compiling (otherwise the developer gets all kinds of hard-to-understand compile errors).

I'm trying to use find_library like this:
       find_library(sdk MacOSX10.4u PATHS /Developer/SDKs)
       message("sdk= ${sdk}")
but the result is 
       sdk= sdk-NOTFOUND
even on a system where the 10.4 sdk is present.

What am I missing?


Thanks,
aaron