Default for CMake Policy CMP<NNNN> when it is otherwise left unset.

Commands cmake_minimum_required(VERSION) and cmake_policy(VERSION) by default leave policies introduced after the given version unset. Set CMAKE_POLICY_DEFAULT_CMP<NNNN> to OLD or NEW to specify the default for policy CMP<NNNN>, where <NNNN> is the policy number.

This variable should not be set by a project in CMake code; use cmake_policy(SET) instead. Users running CMake may set this variable in the cache (e.g. -DCMAKE_POLICY_DEFAULT_CMP<NNNN>=<OLD|NEW>) to set a policy not otherwise set by the project. Set to OLD to quiet a policy warning while using old behavior or to NEW to try building the project with new behavior.