There is such a command for extracting the Stage3 tarball: tar xpvf stage3-*.tar.bz2 --xattrs-include='*.*' --numeric-owner But it doesn't work as Stage3 tarballs in the .tar.xz now, so, no .tar.bz2 files exists. Reproducible: Always
Please read at the URL how to help improve the Handbook.
https://wiki.gentoo.org/wiki/Handbook_Talk:Parts/Installation/Stage#Extracting_XZ-compressed_stage3_tarball