APP status of subordinate charm is always blank

[Nobuto Murata]

neutron-openvswitch as an example below, APP status in `juju status` is always blank. I expect APP status is "active", not blank when workload status of its units are "active".

$ juju status neutron-openvswitch
MODEL CONTROLLER CLOUD/REGION VERSION
default localhost lxd/localhost 2.0-beta16

APP VERSION STATUS EXPOSED ORIGIN CHARM REV OS
neutron-openvswitch false jujucharms neutron-openvswitch 3 ubuntu
nova-compute active false jujucharms nova-compute 3 ubuntu

RELATION PROVIDES CONSUMES TYPE
image-service glance nova-compute regular
neutron-plugin-api neutron-api neutron-openvswitch regular
neutron-plugin neutron-openvswitch nova-compute regular
amqp neutron-openvswitch rabbitmq-server regular
cloud-compute nova-cloud-controller nova-compute regular
neutron-plugin nova-compute neutron-openvswitch subordinate
compute-peer nova-compute nova-compute peer
amqp nova-compute rabbitmq-server regular

UNIT WORKLOAD AGENT MACHINE PUBLIC-ADDRESS PORTS MESSAGE
nova-compute/0 active idle 6 10.0.8.172 Unit is ready
  neutron-openvswitch/0 active idle 10.0.8.172 Unit is ready

MACHINE STATE DNS INS-ID SERIES AZ
6 started 10.0.8.172 juju-3c2daa-6 xenial

[Nobuto Murata (nobuto)]

Indent may be lost, so to be more clear:
$ juju status neutron-openvswitch
...
APP VERSION STATUS EXPOSED ORIGIN CHARM REV OS
neutron-openvswitch *blank* false jujucharms neutron-openvswitch 3 ubuntu
nova-compute active false jujucharms nova-compute 3 ubuntu
...

In yaml format:
$ juju status --format yaml neutron-openvswitch
...
applications:
  neutron-openvswitch:
    charm: cs:xenial/neutron-openvswitch-3
    series: xenial
    os: ubuntu
    charm-origin: jujucharms
    charm-name: neutron-openvswitch
    charm-rev: 3
    exposed: false
    application-status: {}
    relations:
    ...
  nova-compute:
    charm: cs:xenial/nova-compute-3
    series: xenial
    os: ubuntu
    charm-origin: jujucharms
    charm-name: nova-compute
    charm-rev: 3
    exposed: false
    application-status:
      current: active
      message: Unit is ready
      since: 02 Sep 2016 00:14:25+09:00
...

[viswesuwara nathan (viswesn)]

I started working on this ticket. Thanks