hello @Schuby
Unfortunately, multi-arch blocks are not supported currently
So, as you noticed, you can have blocks namespaced by the “arch” you are targeting.
You can use multi-arch image in the dockerfile but you will have to push to different blocks (having default device types matching your arch)
The autohupr is using a multiarch image autohupr-example/Dockerfile at master · balena-io-experimental/autohupr-example · GitHub
but when you push to the block, it only builds for the architecture matching the default device type.
There is an example of how you would instruct your users to use the block GitHub - balena-solutions/display: A blueprint for deploying hardware-accelerated display servers on balenaOS. Serves as a practical example of abstracting graphics stacks. · GitHub
We have a feature request for this Mixed-architecture fleets (and apps) - #3 by system but alas, it has been longstanding