CMAKE_APPLE_SILICON_PROCESSOR ----------------------------- .. versionadded:: 3.19.2 On Apple Silicon hosts running macOS, set this variable to tell CMake what architecture to use for :variable:`CMAKE_HOST_SYSTEM_PROCESSOR`. The value must be either ``arm64`` or ``x86_64``. The value of this variable should never be modified by project code. It is meant to be set as a cache entry provided by the user, e.g. via ``-DCMAKE_APPLE_SILICON_PROCESSOR=...``. See also the :envvar:`CMAKE_APPLE_SILICON_PROCESSOR` environment variable.