> I'm not sure I get the "magic" part The problem I was trying to solve was container signing, as well as building AMD64+ARM64 multi-arch images without buildx

> I'm not sure I get the "magic" part The problem I was trying to solve was container signing, as well as building AMD64+ARM64 multi-arch images without buildx having access to both contexts, i.e. on different VMs (a CircleCI limitation). When you use buildah without bud you learn just how many implicit steps are involved in a Dockerfile, and how those implicit steps have been the problem all along. buildx works great when you're on the razor thin happy path. The abstraction is great for the majority who need it but, crucially, Dockerfiles provide no way to escape the abstractions.