CMAKE_POLICY_DEFAULT_CMP ------------------------------ Default for CMake Policy ``CMP`` when it is otherwise left unset. Commands :command:`cmake_minimum_required(VERSION)` and :command:`cmake_policy(VERSION)` by default leave policies introduced after the given version unset. Set ``CMAKE_POLICY_DEFAULT_CMP`` to ``OLD`` or ``NEW`` to specify the default for policy ``CMP``, where ```` is the policy number. This variable should not be set by a project in CMake code as a way to set its own policies; use :command:`cmake_policy(SET)` instead. This variable is meant to externally set policies for which a project has not itself been updated: * Users running CMake may set this variable in the cache (e.g. ``-DCMAKE_POLICY_DEFAULT_CMP=``). Set it to ``OLD`` to quiet a policy warning while using old behavior or to ``NEW`` to try building the project with new behavior. * Projects may set this variable before a call to :command:`add_subdirectory` that adds a third-party project in order to set its policies without modifying third-party code.