CMP0046ΒΆ
Error on non-existent dependency in add_dependencies.
CMake 2.8.12 and lower silently ignored non-existent dependencies
listed in the add_dependencies() command.
The OLD behavior for this policy is to silently ignore non-existent
dependencies. The NEW behavior for this policy is to report an error
if non-existent dependencies are listed in the add_dependencies()
command.
This policy was introduced in CMake version 3.0. CMake version 3.0.2 warns when the policy is not set and uses OLD behavior. Use the cmake_policy command to set it to OLD or NEW explicitly.