find_darwin_sdk_dir can be slow, especially if xcrun does not immediately find the corresponding SDK (i.e. because it is missing). This skips those checks if the user has already set the corresponding CMake variable to disable the platform anyway.
find_darwin_sdk_dir can be slow, especially if xcrun does not immediately find the corresponding SDK (i.e. because it is missing). This skips those checks if the user has already set the corresponding CMake variable to disable the platform anyway.