Policy CMP0075 is not set during compile

-- Looking for unistd.h

CMake Warning (dev) at /usr/share/cmake-3.16/Modules/CheckIncludeFile.cmake:80 (message):

  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:

    m;crypt;dl;-lpthread

  For compatibility with CMake 3.11 and below this check is ignoring it.

Call Stack (most recent call first):

  zlib/CMakeLists.txt:65 (check_include_file)

This warning is for project developers.  Use -Wno-dev to suppress it.

-- Looking for unistd.h - found