Command Fails: sudo apt-get install linux-image-extra-`uname -r`

view story

http://askubuntu.com – When I run, sudo apt-get install linux-image-extra-`uname -r` I get Reading package lists... Done Building dependency tree Reading state information... Done E: Unable to locate package linux-image-extra-3.10.0-031000rc7-generic E: Couldn't find any package by regex 'linux-image-extra-3.10.0-031000rc7-generic' Well, obviously, it can't find the package. I am trying to install docker, following the instructions found here (I am using 13.04). What should I do? Thank you. P.S. I had to upgrade my kernel as the default kernel did not support my Pixels touchscreen or trackpad (when Ub (HowTos)