Re: using build.sh in src subdirectories

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

   Date: Tue, 14 Jul 2009 19:01:38 -0400
   From: Taylor R Campbell <campbell%mumble.net@localhost>

   Handling destdirs and installworlddirs might pose an issue for
   installing from a single source directory -- I don't know anything
   about how this works, but I imagine that it might take some effort to
   persuade build.sh to copy just those files from the destdir to the
   installworlddir that are relevant, since simply making the install
   target in the desired subdirectory will install files into the
   destdir, not into the installworlddir.

Here's a variation on the theme: I want to build everything on one
machine, say the build-machine, and install patches on another
machine, say the install-machine.  I'd like to do this just by
mounting the source, object, and tool directories of the build-machine
at /usr/src, /usr/obj, and /usr/tools on the install-machine, and then
just running `make install' from /usr/src/foo/bar/baz/bit on the
install-machine.  But that doesn't work if the build-machine's source,
object, and tool directories are located somewhere other than
/usr/src, /usr/obj, and /usr/tools on the build-machine -- all the
.depend files that the install-machine sees will be full of bogus
absolute pathnames.  I can run the make wrapper through a sed script
to fix its pathnames, yielding a new make wrapper to use on the
build-machine, but I can't so easily just make new .depend files
(particularly if I want /usr/obj read-only on the install-machine).

Can I somehow persuade the same machinery that `build.sh install=/'
uses to install only those parts that are relevant to the subtree that
I wanted to rebuild?

I presume that most production installations of NetBSD don't spend
their CPU cycles building NetBSD updates themselves -- if not as I
described, how is this separation usually accomplished?