nanobsd on CURRENT -- can not unmount image in every second build

[Lev Serebryakov]

Hello, Embedded.

  I've started to experiment with NanoBSD-based image for my router
 based on 9-BETA1 sources (I've used 8-STABLE before) and here is
 problem: in every second run it can not finish building image with
 error:

/usr/obj/nanobsd.gateway-net5501//_.mnt/./conf/default/etc/remount
444529 blocks
Filesystem  1K-blocks   Used   Avail Capacity iused  ifree %iused  Mounted on
/dev/md0s1a   3870351 227150 3333573     6%   10711 493575    2%   /usr/obj/nanobsd.gateway-net5501/_.mnt
umount: unmount of /usr/obj/nanobsd.gateway-net5501/_.mnt failed: Device busy

-- 
// Black Lion AKA Lev Serebryakov <lev at FreeBSD.org>