$ docker build -t aarch64_builder aarch64_builder
[+] Building 1.0s (2/2) FINISHED docker:default
=> [internal] load build definition from Dockerfile 0.0s
=> => transferring dockerfile: 2.25kB 0.0s
=> ERROR [internal] load metadata for docker.io/arm64v8/ubuntu:20.04 0.9s
[internal] load metadata for docker.io/arm64v8/ubuntu:20.04:
$ docker pull arm64v8/ubuntu
Using default tag: latest
latest: Pulling from arm64v8/ubuntu
no matching manifest for linux/amd64 in the manifest list entries
This used to work, would be grateful for any advice