Maybe better examples:

rainier:/usr/pkgsrc/fonts/fontconfig$ /usr/sbin/pkg_admin -K /var/db/pkg -b -d /var/db/pkg -s "" lsbest fontconfig
rainier:/usr/pkgsrc/fonts/fontconfig$ pkg_info -e fontconfig
fontconfig-2.2.0
rainier:/usr/pkgsrc/fonts/fontconfig$

reed@k3:/usr/pkgsrc/fonts/fontconfig$ /usr/sbin/pkg_admin -K /var/db/pkg -b -d /var/db/pkg -S lsbest fontconfig
reed@k3:/usr/pkgsrc/fonts/fontconfig$ pkg_info -e fontconfig
fontconfig-2.2.1nb2
reed@k3:/usr/pkgsrc/fonts/fontconfig$

reed@k3:/usr/pkgsrc/fonts/fontconfig$ bmake print-pkg-size-this
1039787
reed@k3:/usr/pkgsrc/fonts/fontconfig$ bmake print-pkg-size-depends
167857

Hmmm... I did a

$ rm work.k3/.install_done
$ bmake PKG_DEBUG_LEVEL=4 -DFORCE_PKG_REGISTER install

And no dc problem and now it works.

$ cat /var/db/pkg/fontconfig-2.2.1nb2/+SIZE_PKG
1039787


I don't know why. I still have empty +SIZE_* files and this did
happen on two different systems.

On one box:

-rw-r--r--    1 root     root            1 Oct 21 16:09
/var/db/pkg/expat-1.95.6nb1/+SIZE_PKG
-rw-r--r--    1 root     root            1 Oct 21 16:07
/var/db/pkg/freetype2-2.1.5/+SIZE_PKG
-rw-r--r--    1 root     root            1 Oct 21 15:54
/var/db/pkg/imake-4.3.0/+SIZE_PKG
-rw-r--r--    1 root     root            0 Oct 21 16:09
/var/db/pkg/expat-1.95.6nb1/+SIZE_ALL
-rw-r--r--    1 root     root            0 Oct 21 16:07
/var/db/pkg/freetype2-2.1.5/+SIZE_ALL
-rw-r--r--    1 root     root            0 Oct 21 15:54
/var/db/pkg/imake-4.3.0/+SIZE_ALL

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