Unused variable warnings issued when CMAKE_POLICY_DEFAULT_ variables are passed via command line
When overriding policy defaults via the command line at project configuration time (documentation https://cmake.org/cmake/help/latest/variable/CMAKE_POLICY_DEFAULT_CMPNNNN.html), will cause CMake to issue a warning about unused variables:
$ cmake .. -DCMAKE_POLICY_DEFAULT_CMP0102="Old"
...
-- Configuring done
-- Generating done
CMake Warning:
Manually-specified variables were not used by the project:
CMAKE_POLICY_DEFAULT_CMP0102
Is this accurate and does this indicate that the variable is not being used/evaluated at all, or is it an erroneous warning?