It could be useful if pkgsrc had an upgrade target to install a package
that is already installed.

It would not deinstall first. It wouldn't do a FORCE_PKG_REGISTER and
cause multiple package registrations for same software.

This would be similar to my package upgrade (for pkg_install) that I PR'd
(#21095) a while ago (and I need to update and put into pkgsrc-wip since
it has been very useful for me).

This "upgrade" option overwrites files. Compares +CONTENTS files and
removes files no longer in new version. Removes pkg data for old package
version. (And maybe run an UPGRADE part of +INSTALL script.)

This was pretty easy for me to implement with pkg_add. But with pkgsrc
this may be difficult. Any ideas?

Anyways, I need this because I dislike using FORCE_PKG_REGISTER when I use
pkgsrc to build new gcc (when it is the only gcc installed). Same problem
with bmake, coreutils, and others.

   Jeremy C. Reed
   http://bsd.reedmedia.net/

p.s. "make update" on my LOCALBASE=/usr systems are very dangerous :)