cmake: set CMP0075 to NEW (for ws2_32.lib in win32) Otherwise cmake complains: Policy CMP0075 is not set: Include file check macros honor CMAKE_REQUIRED_LIBRARIES. Run "cmake --help-policy CMP0075" for policy details. Use the cmake_policy command to set the policy and suppress this warning. CMAKE_REQUIRED_LIBRARIES is set to: ws2_32.lib For compatibility with CMake 3.11 and below this check is ignoring it.