This project contains an image capable of crosscompiling for MacOS ARM64 (and possibly x64, but you'll need to tweak it a bit). The Dockerfile to generate the image can be found in the folder crosscompile/ and the image can be built using the command make crosscompile_img (see the root Makefile)
You can also use the docker image (without the XCode SDK embedded): https://github.com/itrooz/macos-crosscompile/pkgs/container/macos-crosscompile
By building or using the image with the XCode SDK (which is required for using the compilers), you agree to the XCode license terms. Please ensure you have read and understood them first
Note that this project has been made mainly to introduce MacOS ARM64 builds to https://github.com/WerWolv/ImHex/. If you are interested in this project taking a more official/general turn, please open an issue