Do not treat
DEFINITIONS as a built-in directory property.
CMake 3.3 and above no longer make a list of definitions available through the :prop_dir:DEFINITIONS directory property. The :prop_dir:COMPILE_DEFINITIONS directory property may be used instead.
OLD behavior for this policy is to provide the list of flags given so far to the add_definitions command. The
NEW behavior is to behave as a normal user-defined directory property.
This policy was introduced in CMake version 3.3. CMake version |release| warns when the policy is not set and uses
OLD behavior. Use the cmake_policy command to set it to