Comment 2 for bug 1810043

A very similar problem, perhaps the same bug seems to impact the use of vlan interfaces. "netplan apply" fails the first run with the output shown below (and leaves the networking in a bad state) then succeeds the second time it is run.

# netplan apply
Traceback (most recent call last):
  File "/usr/sbin/netplan", line 23, in <module>
    netplan.main()
  File "/usr/share/netplan/netplan/cli/core.py", line 50, in main
    self.run_command()
  File "/usr/share/netplan/netplan/cli/utils.py", line 130, in run_command
    self.func()
  File "/usr/share/netplan/netplan/cli/commands/apply.py", line 43, in run
    self.run_command()
  File "/usr/share/netplan/netplan/cli/utils.py", line 130, in run_command
    self.func()
  File "/usr/share/netplan/netplan/cli/commands/apply.py", line 93, in command_apply
    stderr=subprocess.DEVNULL)
  File "/usr/lib/python3.6/subprocess.py", line 291, in check_call
    raise CalledProcessError(retcode, cmd)
subprocess.CalledProcessError: Command '['udevadm', 'test-builtin', 'net_setup_link', '/sys/class/net/vlan557']' returned non-zero exit status 4.

# netplan apply
(successful the second time)

# lsb_release -d
Description: Ubuntu 18.04.2 LTS

# dpkg -l | grep -i netplan
ii netplan.io 0.40.1~18.04.4 amd64 YAML network conf...

# cat /etc/netplan/network.yaml
network:
  version: 2
  renderer: NetworkManager
  ethernets:
    ext:
      match:
        macaddress: 00:1b:21:xx:xx:xx
      set-name: ext
      mtu: 9000
  vlans:
          vlan557:
                  id: 557
                  link: ext
                  mtu: 9000
                  addresses: [172.16.1.100/22]

(network.yaml edited for privacy and brevity)