... which neatly brings us back to the original question. If Xarchiver (according to its help file) can support creating compressed tar archives, then how do we do it with the version shipped for Mageia 2? lzma is supported in Xarchiver so that could be used for the compression, but where did tar go?
[EDIT]
After a lot of google-type research, and after rebuilding the rpm and building the latest svn (revision 42) of Xarchiver I am forced to conclude that this is a bug. Logged it with bugzilla: Bug 6713 (
https://bugs.mageia.org/show_bug.cgi?id=6713).
Apparently Xarchiver is somewhat prone to this sort of problem. The latest revision doesn't even detect lzma, gz, bz2 and more! And that revision is at least 2 years old!!!
[/EDIT]