IncludeAndLibraryPaths

As noted here, Apple have changed the location of system include files and libraries; they used to be copied from the SDKs to the "standard" /usr/include and /usr/lib either automatically or on command.

The native compilers have been built so you don't need to take any related action to use them: unfortunately, this means that paths in /usr/local and /Library/Frameworks aren't searched.