[CMake] Problems with using libraries that supercede system libraries

[cheshirekow]

> You should set CMAKE_PREFIX_PATH instead of relying on pkgconfig. Then you can 
> be sure that cmake will figure out the stuff in a way that it works (i.e. 
> libraries with full paths).
> 

That worked like a charm. I'm glad there turned out to be a simple
solution.


> > link_directories( ${GTKmm_LIBRARY_DIRS}  )
> 
> You should not need to call link_directories()...

Removed, thanks for the tip.


> ... instead ${GTKmm_LIBRARIES} should be a list of libraries with full path. 
> Is that the case ?
> What does
> message(STATUS "gtkmm: ${GTKmm_LIBRARIES}") give ?

Prior to exporting CMAKE_PREFIX_PATH, it listed full paths to the
libraries and they were /usr/... paths. After setting CMAKE_PREFIX_PATH,
they're all /home/josh/Codes/...


Thanks for the help!

Josh