Fails to find Cg/cg.h

[GoogleCodeExporter]

What steps will reproduce the problem?
1.configure with cmake
2.make
3.fail

What is the expected output? What do you see instead?
package built

What version of the product are you using? On what operating system?
trunk on gentoo linux amd64

Please provide any additional information below.
As you can see Cg/cg.h does exist
ls /opt/nvidia-cg-toolkit/include/Cg/cg.h 
/opt/nvidia-cg-toolkit/include/Cg/cg.h

and 

Cg_INCLUDE_DIR points to /opt/nvidia-cg-toolkit/include/Cg

even when setting Cg_INCLUDE_DIR to /opt/nvidia-cg-toolkit/include/ it still 
fails to find it.

[ 99%] Building CXX object 
Engine/CMakeFiles/OgreKitCore.dir/__/Bin/OgreKitCore/compile_OgreKitCore_0.cpp.o
In file included from 
/home/salamanderrake/src/gamekit/trunk/Ogre-1.9a/PlugIns/CgProgramManager/includ
e/OgreCgProgramFactory.h:31:0,
                 from /home/salamanderrake/src/gamekit/trunk/Ogre-1.9a/PlugIns/CgProgramManager/include/OgreCgPlugin.h:32,
                 from /home/salamanderrake/src/gamekit/trunk/Engine/gkRenderFactory.cpp:78,
                 from /home/salamanderrake/src/gamekit/build/Bin/OgreKitCore/compile_OgreKitCore_0.cpp:30:
/home/salamanderrake/src/gamekit/trunk/Ogre-1.9a/PlugIns/CgProgramManager/includ
e/OgreCgPrerequisites.h:32:19: fatal error: Cg/cg.h: No such file or directory
 #include <Cg/cg.h>
                   ^
compilation terminated.
make[2]: *** 
[Engine/CMakeFiles/OgreKitCore.dir/__/Bin/OgreKitCore/compile_OgreKitCore_0.cpp.
o] Error 1
make[1]: *** [Engine/CMakeFiles/OgreKitCore.dir/all] Error 2
make: *** [all] Error 2

Original issue reported on code.google.com by [email protected] on 3 Jan 2014 at 4:45