[CMake] Bump -- CMAKE_INSTALL_PREFIX weirdness.

[Bill Hoffman]

kent williams wrote:
> http://public.kitware.com/Bug/view.php?id=7084
> 
> I made the simplest possible library project, and then messed it up
> based on our build system just enough to reproduce the error. ;-)
> 
> Now obviously, what is done in this project -- Calling Cmake from make
> to batch-configure projects -- might be off-label usage for CMake.
> But the little test project demonstrates something annoying and a bit
> disturbing: Running cmake twice with the same command line parameters
> works for an empty build directory, and fails for an already existing
> build directory.
> 

So, what is happening is that CMake things you have swapped compilers 
and it deletes the cache.   That is so try-compiles get re-run with a 
new compiler.   However, the effect is that it also deletes the -D stuff 
from the command line.  If your rule did not set the compiler it would 
work better.  I will see if I can come up with a fix for this.  However, 
I would recommend you run cmake as a shell script, and use CC and CXX 
environment variables to set the compiler and not -D options.  That 
should be a viable workaround.

-Bill