Was following instructions from PC Linux Magazine, July 2012 article by AndrzejL titled "Forgot To Run aptupgrade? Don't Panic!".
Thanks to those who have offered info and said Welcome. unxz is a command; unxx is not. (btw the man page for "xz" is over 1300 lines). Please let me know if or where I should move this post, as it seems poorly located here.
I doubt anyone would want to analyze why this won't work, but anyway, the command below: unxz (or xz --decompress) seems to me to have nothing to work on; Upon using ls -la, all that's newly created in the /root directory (by the previous two commands) is: aptupgrade-1.0-7pclos2011.src.rpm The unxz... command returns a repeat of the command (naturally), with "file not found"
AndrzejL's Article cli mat'l follows (all rights reserved):
Open a terminal and run:
wget -c http://andrzejl.cyryl.net/WoTW/WoTW_files/aptupgrade/aptupgrade-1.0-7pclos2011.src.rpm
rpm -ivh /root/aptupgrade-1.0-7pclos2011.src.rpm
tar xvf ./aptupgrade-1.0.tar
rpm -ivh --nodeps --force --ignorearch --ignoresize --ignoreos ./*.rpm
rm -f /root/aptupgrade-1.0-7pclos2011.src.rpm
rm -Rf /root/rpmbuild/
BE CAREFUL WHILE USING THE RPM COMMANDS!