pkgtools and xz compressor

[b. f.]

>I notice FreeBSD 7.2's pkg_add, pkg_create, etc don't have support for
>the xz compressor, evidently due to lack of support for the xz format
>in bsdtar.  Does bsdtar support xz in FreeBSD 8.0?  Failing that, is
>xz support for the pkgtools something being looked at in future?
>

Yes, we know, we know.  :)  No, FreeBSD 8.0 does not have support for
lzma compression in it's base system libarchive, although there are
several ports that support it, and it could be handled by using one of
them, as is done with the current USE_ZIP knob.  The latest version of
libarchive (imported recently into 9-CURRENT, from
http://code.google.com/p/libarchive/ ) has support for lzma
compression in several formats, as well as other improvements.
Unfortunately, the imported version of libarchive still has lzma
disabled by default, and no supporting lzma libraries were imported.
You would have to ask kientzle@ why this is so.

>xz's compression ratios tend to be much better than bzip2's, eg.

Yes, and with faster decompression, albeit at the cost of more memory
and cpu usage.  But, unfortunately, portmgr@ does not seem interested
in incorporating these improvements.  If I recall correctly, there are
one or more open PRs suggesting means of adding support, but they have
been largely ignored.  Some time ago, the maintainer of one
widely-used port switched it over to an lzma-compressed tarball, and
received a lot of criticism for doing so, including some from key
committers who evidently didn't even know what lzma was.  Ultimately,
he had to revert to a bzip2-compressed tarball.  So it may be a while
before this is widely used in ports.

b.