pkgsrc-created user and group ids

[Taylor R Campbell <campbell%mumble.net@localhost>]

(I am not subscribed to this list, so please cc me in replies.)

I'm using pkgsrc on NetBSD.  I'd like pkgsrc-created user and group
ids to lie in a particular interval.  (That way, for example, I can
avoid overlap in pkg_comp chroots between the host environment's ids
and the chroot environment's ids.)  I can do this for user ids by
putting `range a..b' in /etc/usermgmt.conf, but I see no obvious way
to make this work for group ids.

Setting GROUPADD in mk.conf to an invocation of groupadd(8) with the
`-r' option doesn't work, because GROUPADD is used as a pathname, not
as a command invocation.  And a cursory examination of the source in
src/usr.sbin/user suggests no other way to give groupadd(8) an
interval of gids.

Ideas?