I'm facing a similar situation with building a focal autopkgtest container on s390x:
$ autopkgtest-build-lxd ubuntu-daily:focal/s390x Creating autopkgtest-prepare-wDa Starting autopkgtest-prepare-wDa Created symlink /<email address hidden> → /dev/null. Timed out waiting for container to boot
$ autopkgtest-build-lxd ubuntu:focal/s390x Creating autopkgtest-prepare-ZX9 Starting autopkgtest-prepare-ZX9 Created symlink /<email address hidden> → /dev/null. Timed out waiting for container to boot
I'm facing a similar situation with building a focal autopkgtest container on s390x:
$ autopkgtest- build-lxd ubuntu- daily:focal/ s390x prepare- wDa prepare- wDa
Creating autopkgtest-
Starting autopkgtest-
Created symlink /<email address hidden> → /dev/null.
Timed out waiting for container to boot
$ autopkgtest- build-lxd ubuntu:focal/s390x prepare- ZX9 prepare- ZX9
Creating autopkgtest-
Starting autopkgtest-
Created symlink /<email address hidden> → /dev/null.
Timed out waiting for container to boot