Building pkgsrc packages for another host without bulk builds

How to build pkgsrc packages on a build host, on-demand (no (partial?) bulk builds)

Rational:

Simple solution: make package, for the the package itself and the dependencies:

/etc/mk.conf

DEPENDS_TARGET=         install package

Then:

cd /usr/pkgsrc/category/PACKAGE
make install package

will create the packages for PACKAGE and its dependencies.

To create the pkg_summary.gz, needed for pkgin:

cd /usr/pkgsrc/packages/All
pkg_info -X -a > pkg_summary
gzip -f pkg_summary

Caveat: "warning: package PACKAGE has an empty FILE_SIZE on repository"

The pkg_summary misses the sizes of the packages. There must be a better way to generate pkg_summary (tell me if you know). I can live with that atm.