Unable to locate package ros-groovy-desktop-full
My ubuntu linux is 12.04. And I want to install ROS, but when I followed the instruction in ros.org , in the step of "sudo apt-get install ros-groovy-desktop-full", I got this problem "Unable to locate package ros-groovy-desktop-full". And I tried other version of ROS such as hydro and diamondback and other version of ubuntu such as 12.10, this problem can not be solved.