bashbrew-arch   variants
amd64    jessie,jessie-slim,alpine,onbuild,stretch,stretch-slim
arm32v6  jessie,jessie-slim,alpine,onbuild,stretch,stretch-slim
arm32v7  jessie,jessie-slim,alpine,onbuild,stretch,stretch-slim
arm64v8  jessie,jessie-slim,alpine,onbuild,stretch,stretch-slim
i386     jessie,jessie-slim,alpine,onbuild,stretch,stretch-slim
ppc64le  jessie,jessie-slim,alpine,onbuild,stretch,stretch-slim
s390x    jessie,jessie-slim,alpine,onbuild,stretch,stretch-slim