Howdy.
I have an appliance in which /sbin/start_udev exists but does not run
successfully:
/sbin/start_udev: line 36: /etc/init.d/functions: No such file or directory
This prevents the "modprobe virtio_net" line (among other things) from
being invoked. The attached patch is what I'm applying locally to
libguestfs-1.0.74 to work around the impact of this issue.