Fatal error on relative paths in INCLUDE_DIRECTORIES target property.
CMake 188.8.131.52 and lower allowed the INCLUDE_DIRECTORIES target property to contain relative paths. The base path for such relative entries is not well defined. CMake 2.8.12 issues a FATAL_ERROR if the INCLUDE_DIRECTORIES property contains a relative path.
The OLD behavior for this policy is not to warn about relative paths in the INCLUDE_DIRECTORIES target property. The NEW behavior for this policy is to issue a FATAL_ERROR if INCLUDE_DIRECTORIES contains a relative path.
This policy was introduced in CMake version 2.8.12. CMake version 3.6.2 warns when the policy is not set and uses OLD behavior. Use the cmake_policy command to set it to OLD or NEW explicitly.
OLD behavior of a policy is
deprecated by definition
and may be removed in a future version of CMake.