[CMake] GCC version change problems

[Bill Hoffman]

Corrie wrote:
> Please pardon my crossposts :
>
> I completely deleted my build directory, then made a new one, cd' to 
> it, and ran ccmake against ../vtk
Try that again, but this time set the following environment variables 
before running cmake.

CC=/path/to/gcc/you/want
CXX=/path/to/c++/you/want

Both of those should be full paths to working compilers.

-Bill