As we talked about with Judd on irc, that should be nice to drop libtar fully and use libarchive instead of libtar. First
1. libtar is obsolote and not activly developed. 2. libtar got many limits, which isn't good in future
About libarchive: 1. libarchive activly developed project (http://people.freebsd.org/~kientzle/libarchive/) 2. libarchive supports many compression formats. Eg.: targz, tarbz2, zip, etc.. 3. Better documentation available for it. 4. It got shared and static library too.
We are using a patched pacman in frugalware which utilizes libarchive, and we are using a mixed package compression type. (Eg.: We got bz2 compressed and gzip compressed packages too)
At us the pacman libarchive patch was fully backward compatible with old pacman. No package changes or recompile was needed.
My first libarchive patch is about to use libarchive in pacman-lib cvs instead of libtar. The mixed enviroment works at us, because we got a .fpm extension for packages, but in arch you got .tar.gz and i think need a little experimence to find out how can we integrate mixed packages into archlinux. (if it is needed)
The patch is attached against latest CVS.
(Oops. in this patch you can find a fix for Makefile.am which is in scripts/ dir. (Added pacman-optimize to makefile.am)
I can not test this patch, (just only it is compile fine) originaly was rewritten of our pacman patch (frugalware) so please test it with archlinux. Test everything. The backward compatibility, etc.. I can not test it, because in frugalware we got "tons" of specific patches for pacman.
I'm waiting for you answer.
Christian Hamar alias krix Hungary Frugalware Development Team