Install ros-hydro-rqt failed.
system: ubuntu 12.04 LTS ROS version 1.9.54 I try to install ros-hydro-rqt, but failed.
sudo apt-get install ros-hydro-rqt
Failed to fetch http:packages.ros.org/ros/ubuntu/pool/main/r/ros-hydro-rqt/ros-hydro-rqt_0.2.13-0precise-20140130-2154-+0000_amd64.deb Something wicked happened resolving 'packages.ros.org:http' (-5 - No address associated with hostname)
E: Unable to fetch some archives, maybe run apt-get update or try with --fix-missing?