[CMake] cmake is reruning on rebuild

[Bill Hoffman]

David Cole wrote:
> Just use Build Solution. Rebuild Solution causes *all* build steps 
> everywhere to re-run, even when nothing has changed, including the ones 
> that re-run cmake if a CMakeLists.txt file changes.
> 
> If you want to start over entirely (effective "Rebuild Solution") then 
> wipe your binary tree entirely, re-run CMake to generate a new solution 
> file and open that solution and do "Build Solution".....
> 

This might be an issue:
add_subdirectory(../A "${CMAKE_BINARY_DIR}")

That really should be:

add_subdirectory(../A A_build)

I have seen an issue where cmake writes two conflicting build files into 
that directory.   ${CMAKE_BINARY_DIR} will automatically be added to 
A_build anyway.


-Bill