Linux relies on Docker for mac to build it's templates.
After files are built, replace linuxtemplate.tar.gz and raspbiantemplate.tar.gz to build apps with
your custom code.
To build everything run. This will build templates and linux simulator.
./build_template.sh
You would also need Raspbian binaries to build cross-compiled template for Raspbian Pi. You can download them here.
Note, that build_template.sh runs on macOS, while build_template_linux.sh runs inside Docker container on Linux. You can comment out parts of the script to make build faster.