Description

Import fails when the tarball doesn't contain all the architectures of a multi-arch image.

This is analogous to a previous issue with export #2590

Steps to reproduce the issue:

1. ctr images pull docker.io/library/busybox:latest
2. ctr images export busybox.tar docker.io/library/busybox:latest
3. ctr images import --base-name docker.io/library/busybox busybox.tar

Describe the results you received:

ctr: content digest sha256:b37971a5af7cc52577de16b0916f2f65ff84ed3852d5d0f3e6a8ab89b443eedb: not found

Describe the results you expected:

The image is successfully imported for the provided architecture.

Output of containerd --version:

containerd github.com/containerd/containerd v1.2.0-281-gac2cc2af.m ac2cc2af613595686beec52231dbedfaa7c15b69.m