From: Lubomir Sedlacik <salo@Xtrmntr.org>

  On Wed, Dec 03, 2003 at 09:39:05AM -0800, Jeremy C. Reed wrote:
  > It could be useful if pkgsrc had an upgrade target to install
  > a package that is already installed.

  "make replace" ?

That doesn't quite do it, since the   existing package is deleted
before the new one is installed.  I think Jeremy would like the new
files to be installed over the old ones (by copying to the fs, and
then rename(2), so even if the system crashes things are at least in a
possibly working state), and following that garbage collect the files
that were in the old but not the new package.  make replace comes
closer than make update, but it still deinstalls first, leaving a
window where the file doesn't exist.

This won't work for a 100% pkgsrc system with make in a package, which
I think was Jeremy's point.

-- 
        Greg Troxel <gdt@ir.bbn.com>