oasis rofl build without builder should just fail on macOS #652
Description
This was suggested by one of our hackathoners:
Since oasis rofl build cannot work natively on macOS (and windows?) if no artifacts.builder is defined, it should simply crash saying sth like
Error: Building ROFL natively on {platform.os}_{platform.architecture} is not supported yet. Invoke the command inside a container:
docker/podman run --platform linux/amd64 --volume .:/src -it ghcr.io/oasisprotocol/rofl-dev:main oasis rofl build ... and any flags
Currently it goes on complaining that some library is missing etc.