Troubles w/ `tar.xz` files and Paludis

An attempt to upgrade my KDE to fresh 4.8.2 was unexpectedly failed with strange error at unpack stage:

>>> Starting src_unpack
>>> Unpacking kdelibs-4.8.2.tar.xz to /storage/tmp/paludis/kde-base-kdelibs-4.8.2/work
xz -dc /storage/soft/gentoo/distfiles/kdelibs-4.8.2.tar.xz | tar xf - --no-same-owner

Error:
* In program cave perform install --hooks --managed-output --output-exclusivity with-others =kde-base/kdelibs-4.8.2:4::gentoo --destination installed --replacing =kde-base/kdelibs-4.8.2:4::installed --x-of-y 1 of 1:
* When installing 'kde-base/kdelibs-4.8.2:4::gentoo' replacing { 'kde-base/kdelibs-4.8.2:4::installed' }:
* When running an ebuild command on 'kde-base/kdelibs-4.8.2:4::gentoo':
* Install failed for 'kde-base/kdelibs-4.8.2:4::gentoo' (paludis::ActionFailedError)

unpack: error: Couldn't unpack /storage/soft/gentoo/distfiles/kdelibs-4.8.2.tar.xz: 141 0
unpack: making ebuild PID 28947 exit with error
die trap: exiting with error.

Failed install to / for kde-base/kdelibs-4.8.2:4::gentoo replacing 4.8.2:4::installed

To fix that u have to fix paludis script to unpack sources in /usr/libexec/paludis/utils/unpack and function unpack_tar.xz(). !

Upd: That was a “long” time ago :) Nowadays everything is Ok (paludis 0.78.1 and KDE 4.9).