On MacOSX, pkg_add does not work:

masahiro@lucernhammer[All] pkg_add openssl-0.9.6e.tgz 
/usr/bin/gnutar: unrecognized option `--fast-read'
Try `/usr/bin/gnutar --help' for more information.
pkg_add: gnutar extract of /Volumes/UFS/pkgsrc/packages/All/openssl-0.9.6e.tgz failed!
pkg_add: unable to extract table of contents file from `/Volumes/UFS/pkgsrc/packages/All/openssl-0.9.6e.tgz' - not a package?

	Adding "-DTAR_MISSING_FAST_READ" to pkg_install/Makefile.inc
	works as a workaround for this, but I met yet another error as
	follows:

masahiro@lucernhammer[ALL] sudo pkg_add  openssl-0.9.6e.tgz 
zsh: no such file or directory: /usr/pkg/sbin/mtree
pkg_add: mtree returned a non-zero status - continuing
...

	I can't find mtree command in pkgsrc tree (pkglocate did not
	find it).  However, it seems that pkg_install/add/perform.c
	assumes that mtree should be located on the same path of pkg_add
	(i.e. BINDIR).  Did I miss out something?

masahiro