Give build.sh an argument with the Dart project folder and it will output executables for darwin-arm64, linux-amd64 and linux-aarch64.
Assumes host is MacOS, and docker with dockerx plugin and colima are installed. I do not use Docker Desktop.
brew install docker
brew install colima
colima start
curl -LO https://github.com/docker/buildx/releases/download/v0.17.1/buildx-v0.17.1.darwin-arm64
chmod +x buildx-v0.17.1.darwin-arm64
sudo mv buildx-v0.17.1.darwin-arm64 /usr/local/bin/docker-buildx
/usr/local/bin/docker-buildx version
mkdir -p ~/.docker/cli-plugins
ln -s /usr/local/bin/docker-buildx ~/.docker/cli-plugins/docker-buildx
docker buildx version
docker context use colimaPublic domain.