Comment 8 for bug 1964481

Focal looking good as well. I've tested netplan.io 0.104-0ubuntu2~20.04.1 from focal-proposed and attached the autopkgtest logs to the bug description.

root@ff-nm:/x# apt list *netplan*
Listing... Done
libnetplan-dev/focal-proposed,now 0.104-0ubuntu2~20.04.1 amd64 [installed]
libnetplan0/focal-proposed,now 0.104-0ubuntu2~20.04.1 amd64 [installed,automatic]
netplan.io/focal-proposed,now 0.104-0ubuntu2~20.04.1 amd64 [installed]

Additional Focal/Core20 testing:
root@ff-nm:/x# make -j8 check # running test-suite on netplan enabled NetworkManager
[...]
============================================================================
Testsuite summary for NetworkManager 1.22.10
============================================================================
# TOTAL: 843
# PASS: 837
# SKIP: 6
# XFAIL: 0
# FAIL: 0
# XPASS: 0
# ERROR: 0
============================================================================

root@ff-nm:/x# nmcli con add type ethernet con-name SRU-test
Connection 'SRU-test' (b1938133-9749-4f20-878c-91442f95500c) successfully added.
root@ff-nm:/x# nmcli c
NAME UUID TYPE DEVICE
SRU-test b1938133-9749-4f20-878c-91442f95500c ethernet --
netplan-eth1 8bf25856-ca0b-388e-823c-b898666ab9d2 ethernet --
root@ff-nm:/x# netplan get
network:
  version: 2
  ethernets:
    eth0:
      dhcp4: true
    eth1:
      renderer: NetworkManager
      dhcp4: true
    NM-b1938133-9749-4f20-878c-91442f95500c:
      renderer: NetworkManager
      match: {}
      dhcp4: true
      dhcp6: true
      ipv6-address-generation: "stable-privacy"
      wakeonlan: true
      networkmanager:
        uuid: "b1938133-9749-4f20-878c-91442f95500c"
        name: "SRU-test"
        passthrough:
          connection.permissions: ""
          ethernet.mac-address-blacklist: ""
          ipv4.dns-search: ""
          ipv6.dns-search: ""
          ipv6.ip6-privacy: "-1"
          proxy._: ""
root@ff-nm:/x# ll /etc/netplan/
total 20
drwxr-xr-x 2 root root 4096 Mar 23 12:07 ./
drwxr-xr-x 101 root root 4096 Mar 23 11:56 ../
-rw-r--r-- 1 root root 389 Oct 5 10:08 50-cloud-init.yaml
-rw-r--r-- 1 root root 81 Feb 22 14:16 70-netplan-set.yaml
-rw-r--r-- 1 root root 551 Mar 23 12:07 90-NM-b1938133-9749-4f20-878c-91442f95500c.yaml

The regression in initramfs-tools (arm64) reported by the Ubuntu SRU Bot as a test environment failure and got fixed by retry.