message: doc: note on SDK for macOS depends cross-compile
diff: @@ -49,6 +49,11 @@ The paths are automatically configured and no other options are needed unless ta
  sudo apt-get install curl librsvg2-bin libtiff-tools bsdmainutils cmake imagemagick libz-dev python3-setuptools libtinfo5 xorriso
  +Note: You must obtain the macOS SDK before proceeding with a cross-compile.
  +Under the depends directory, create a subdirectory named `SDKs`.
  +Then, place the extracted SDK under this new directory.
  +For more information, see [SDK Extraction](../contrib/macdeploy/README.md#sdk-extraction).
  +
  #### For Win64 cross compilation
  - see [build-windows.md](../doc/build-windows.md#cross-compilation-for-ubuntu-and-windows-subsystem-for-linux)
  