Can't get mdev rule to match ethernet interfaces

[Mark Hills]

Alpine Linux documentation [1] explains using busybox 'nameif' to rename 
ethernet devices.

But it appears 'mdev' doesn't invoke the command:

  $ mdev -s -v 2>&1 | grep nameif
  [nothing]

/etc/mdev.conf looks like:

  -SUBSYSTEM=net;DEVPATH=.*/net/.*;.* root:root 0600 @/sbin/nameif -s

Note the change to 0600 octal, just in case. We also tried increasingly 
less-specific matches, without success:

  SUBSYTEM=net;.*
  net/.*
  net/(.*)

Using ".*" does actually work. So it proves it is capable (using correct 
config etc.) but of course invokes the command excessively:

  # mdev  -s -v 2>&1 | grep nameif
  mdev: running: /sbin/nameif -s
  mdev: running: /sbin/nameif -s
  mdev: running: /sbin/nameif -s
  [...]

Is this a busybox bug, or have I been misled by the Alpine docs? What is 
the correct match?

I found only very little information on mdev.conf, just the brief message 
in the "--help" message, please let me know if there is more somewhere.

Many thanks,

[1] https://wiki.alpinelinux.org/wiki/Custom_network_interface_names

-- 
Mark