Comment 9 for bug 1979951

On focal, the autopkgtest regressions were all resolved with retries. I verified this fix for focal using LXD container:

root@focal:~# apt-cache policy systemd
systemd:
  Installed: 245.4-4ubuntu3.18
  Candidate: 245.4-4ubuntu3.18
  Version table:
 *** 245.4-4ubuntu3.18 500
        500 http://archive.ubuntu.com/ubuntu focal-proposed/main amd64 Packages
        100 /var/lib/dpkg/status
     245.4-4ubuntu3.17 500
        500 http://archive.ubuntu.com/ubuntu focal-updates/main amd64 Packages
     245.4-4ubuntu3.15 500
        500 http://security.ubuntu.com/ubuntu focal-security/main amd64 Packages
     245.4-4ubuntu3 500
        500 http://archive.ubuntu.com/ubuntu focal/main amd64 Packages
root@focal:~# cat /etc/netplan/10-lxc.yaml
network:
  version: 2
  ethernets:
    eth0:
      dhcp4: true
      dhcp-identifier: mac
    lo:
      addresses: ["10.10.10.17/24","10.10.10.19/24"]
root@focal:~# netplan apply
root@focal:~# ip addr show dev lo
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet 10.10.10.17/24 brd 10.10.10.255 scope global lo
       valid_lft forever preferred_lft forever
    inet 10.10.10.19/24 brd 10.10.10.255 scope global secondary lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host
       valid_lft forever preferred_lft forever
root@focal:~# netplan apply
root@focal:~# ip addr show dev lo
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet 10.10.10.17/24 brd 10.10.10.255 scope global lo
       valid_lft forever preferred_lft forever
    inet 10.10.10.19/24 brd 10.10.10.255 scope global secondary lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host
       valid_lft forever preferred_lft forever