On Tue, Jan 3, 2017 at 11:29 AM, René J.V. Bertin <rjvber...@gmail.com> wrote: > On Tuesday January 03 2017 10:36:54 Robert Maynard wrote: > > That's all nice and well but a bit delicate to expect from an unknown number > of project to adapt their minimum required CMake version for a policy they > probably don't even know they require. > > >> The minimum cmake version of each project controls the default state >> of the policies. So for policy 25 you need a minimum of CMake 3.0. >> This is partially a moot point, because compiler feature detection was >> added in CMake 3.0, so if you are expecting that feature to exist you >> should be requiring CMake 3.0. > > Maybe, indeed, but that becomes a much less trivial point if the policy > becomes necessary somewhere hidden deep in a module that's loaded somewhere > well into running cmake. How is the user supposed to understand what happens > from the error message?
It is the responsibility of the project to understand what components of CMake they require, and correctly specify a cmake_minimum required that satisfies all those requirements. In this case to use compile features you need a minimum of 3.0 which also automatically enables policy 25. > > The point would be moot if the minimum required cmake version could be > adjusted whenever necessary, or policy 25 could be set when required. You can explicitly do both of those things currently see: https://cmake.org/cmake/help/v3.0/manual/cmake-policies.7.html > Or indeed if a cmake installation can be configured locally to set a policy, > or to apply a limit to how far back the minimum required version can be set. > > R. > -- Powered by www.kitware.com Please keep messages on-topic and check the CMake FAQ at: http://www.cmake.org/Wiki/CMake_FAQ Kitware offers various services to support the CMake community. For more information on each offering, please visit: CMake Support: http://cmake.org/cmake/help/support.html CMake Consulting: http://cmake.org/cmake/help/consulting.html CMake Training Courses: http://cmake.org/cmake/help/training.html Visit other Kitware open-source projects at http://www.kitware.com/opensource/opensource.html Follow this link to subscribe/unsubscribe: http://public.kitware.com/mailman/listinfo/cmake-developers
