cannot properly manage IPv6 port

[nivex]

I was able to use nvmet to create an IPv6 port:

root@athens:~# nvmet port add 1 tcp [::]:4420
root@athens:~# nvmet port add-subsystem 1 nqn.2000-12.net.nivex:storage.donatello

but on completion nvmet cannot see what it has done:

root@athens:~# nvmet port show
Configured ports: 0

It does complete successfully:

root@athens:/sys/kernel/config/nvmet/ports/1# grep '' addr_*
addr_adrfam:ipv6
addr_traddr:::
addr_treq:not specified
addr_trsvcid:4420
addr_trtype:tcp

I see tcp/4420 listening and I'm able to connect from the initiator.

This unfortunately also means the state that gets saved does not include port information:

root@athens:~# nvmet state save /tmp/nvmet.state 
Sucessfully written current state to file.
root@athens:~# cat /tmp/nvmet.state 
version: 0
subsystems:
  nqn.2000-12.net.nivex:storage.donatello:
    model: Linux
    serial: d3a05bc4e228683cdbfc
    allowed_hosts: []
    namespaces:
      1:
        enabled: true
        device_path: /dev/dm-2
        device_uuid: 979c4591-d634-4235-a2da-74c0e3d8b3d5
        device_nguid: 00000000-0000-0000-0000-000000000000
ports: {}

Trying to edit the YAML by hand to force a restore also fails:

root@athens:~# nvmet state clear
Sucessfully cleared configuration: 1 state changes.
root@athens:~# cat /tmp/nvmet.state 
version: 0
subsystems:
  nqn.2000-12.net.nivex:storage.donatello:
    model: Linux
    serial: d3a05bc4e228683cdbfc
    allowed_hosts: []
    namespaces:
      1:
        enabled: true
        device_path: /dev/dm-2 
        device_uuid: 979c4591-d634-4235-a2da-74c0e3d8b3d5
        device_nguid: 00000000-0000-0000-0000-000000000000
ports:
  1:
    port_type: Tcp
    port_addr: '[::]:4420'
    subsystems:
    - nqn.2000-12.net.nivex:storage.donatello

root@athens:~# nvmet state restore /tmp/nvmet.state 
Error: Failed to apply state delta between current and saved state

Caused by:
    0: Failed to create directory of port 1
    1: File exists (os error 17)