[Monitorix-general] Odd issue with libvirt MACs

[mr2dave <mr...@gm...>]

On a Fedora 30 box running a bunch of libvirt VMs and monitorix 3.11.0
from Fedora's repo monitorix failed to monitor VM network usage, and I
saw things like "libvirt::libvirt_update: invalid MAC address
'52:54:00:56:3f:6f' in 'pihole'." in the log.

So I double check the MAC address:
[root@saturn ~]# virsh domiflist pihole
 Interface   Type     Source   Model    MAC
-----------------------------------------------------------
 vnet3       bridge   br0      virtio   52:54:00:56:3f:6f

I also checked /var/log/audit/audit.log but didn't see anything related
and tried making selinux permissive just to be sure, but selinux isn't
the problem.

I commented out the MAC validation section in libvirt.pm and changed
$vnet to $vn thrice in the domifstat section just below that, and it
works properly now.
I don't know why the validation is failing, but I'd love to help fix
it.
Is there anything else I can provide or test?