[cmake-developers] Fwd: CMake System Prefix Path

[Brad King]

On 10/25/2013 10:04 AM, Stephen Kelly wrote:
> Brad King wrote:
> 
>> Others have asked to drop CMAKE_INSTALL_PREFIX from the
>> CMAKE_SYSTEM_PREFIX_PATH before.  I think it is a good
>> default for the common dependency-sequence-to-one-prefix
>> use case, but we should have an option to block it.
> 
> Can you choose an interface for blocking it?

It needs to be something that both

* Modules/Platform/UnixPaths.cmake:
  CMAKE_SYSTEM_PREFIX_PATH

* Modules/Platform/WindowsPaths.cmake:
  CMAKE_SYSTEM_PREFIX_PATH
  CMAKE_SYSTEM_LIBRARY_PATH

will see and that the user can set at the command line without
modifying the project.  Therefore we should just test a variable
that users can add to their local cache or that projects can
set before the first language gets enabled (before enable_language
or project).

Other find behavior is controlled by CMAKE_FIND_* settings, so
how about "-DCMAKE_FIND_NO_INSTALL_PREFIX=1"?

-Brad