I am trying to follow the instructions for 'Updating a stable NetBSD
Release' (http://www.netbsd.org/Documentation/updating.html).  It
all seems to work well except for the 'Updating the userland' step.

I am new to the NetBSD build process, but I am familiar with the
'buildworld' and 'installworld' targets for FreeBSD.  The docs
suggest to use 'build.sh -d' to build and install the updated
userland, but doing that gives an error message that '-d' should
only be used with a non-root DESTDIR.  Building into another DESTDIR
works (this seems similar to 'buildworld' under FreeBSD), but what
is the correct method to install the new userland into '/' (what is
the 'installworld' step)?

Something that did seem to work for me is just do 'build.sh' (no
arguments) - it seems to build and install everthing but '/etc'
into '/'.  Following that with an 'etcupdate' appeared to work, but
is this considered a supported method for updating the userland?

If possible, however, I would prefer to update the userland in two
steps:

1. build into non-root DESTDIR
2. install (single user) using the new build or release tarballs.

Any suggestions for the correct use of 'build.sh' or 'make' to
accomplish this?

Thanks in advance,
Cory.