Ok, I'm the guy who submitted those patches so 'make bin-install'
works consistently down through dependencies, making everything
from source that has to be, and installing everything from
packages that can be.  It works well and I can just write one
big metapackage that depends on the packages I like to use, and
'make bin-install' on a new machine gets them all in place with
about the minimal necessary expense of cycles.

Only now ...

I want to add three lines to mk.conf.

PKG_OPTIONS.qt3=cups
PKG_OPTIONS.kdelibs=cups
PKG_OPTIONS.xfce4-print=cups

That means I somehow want the pkg_add attempt to be skipped (or to
fail) for the affected packages, forcing them to be built from
source with the needed options.  I'm still happy to have their
dependencies (without variant options) installed from packages.
Possibly resetting BINPKG_SITES= for just the affected packages
would do the trick; unless they were found in the local package
repository (presumably already built with the right options),
they would have to be built from source. Perhaps this is a way
the framework should behave by default when the target is
bin-install but the PKG_OPTIONS are nonempty.

Does anyone know of an existing feature in pkgsrc that can be
readily (ab)used to accomplish this?  Maybe there should be a
general solution for it worked into bsd.pkg.mk, but right now
that isn't what I want to be working on, I have a machine that
wants packages installed. :)

-Chap