target_link_libraries() reports error if its only argument
is not a target.
In CMake 2.8.2 and lower the
target_link_libraries() command silently
ignored if it was called with only one argument, and this argument
wasn’t a valid target. In CMake 2.8.3 and above it reports an error
in this case.
This policy was introduced in CMake version 2.8.3. CMake version
3.19.8 warns when the policy is not set and uses
OLD behavior. Use
cmake_policy() command to set it to
OLD behavior of a policy is
deprecated by definition
and may be removed in a future version of CMake.