What is the problem or limitation you are having?

Building a linux system package is currently limited to the architecture of the machine building the package. So, an x86_64 machine can only build packages for x86_64. A likely desired scenario is building for aarch64/arm64 on x86_64.

ref: #1106 (comment)

Describe the solution you'd like

The linux system package build process already supports targeting arbitrary distros with Docker; we should extend this to support arbitrary architectures via the buildx Docker builder.

https://docs.docker.com/build/building/multi-platform/

Describe alternatives you've considered

buildx uses QEMU to emulate other arches; so, a VM for the desired arch can be manually created and used to build an app.

Additional context

No response