Comment 0 for bug 1967084

As part of our ubuntu core integration testing we run the spread test for netplan on a PI device.

On this device our test fails with:
"""
2022-03-25 14:33:00 Error executing external:ubuntu-core-20-arm-32:tests/core/netplan-cfg (external:ubuntu-core-20-arm-32) :
-----
+ echo 'Getting version works'
Getting version works
+ snap get system system.network.netplan.network.version
+ MATCH '^2$'
+ echo 'Getting the full document works and it is valid json'
Getting the full document works and it is valid json
+ jq .
+ snap get -d system system.network.netplan
{
  "system.network.netplan": {
    "network": {
      "ethernets": {
        "eth0": {
          "dhcp4": true,
          "match": {
            "macaddress": "b8:27:eb:41:42:43"
          },
          "set-name": "eth0"
        }
      },
      "version": 2
    }
  }
}
+ echo 'Check that setting adding a br54 interface via netplan works'
Check that setting adding a br54 interface via netplan works
+ snap set system system.network.netplan.network.bridges.br54.dhcp4=true
error: cannot perform the following tasks:
- Run configure hook of "core" snap (run hook "configure": cannot try netplan config: no specific reason returned from netplan)
-----
"""

This error means that snapd called io.netplan.Netplan.Config.Set and got a "false" without an error from that call (c.f. https://github.com/snapcore/snapd/blob/master/overlord/configstate/configcore/netplan.go#L218)