Hi,
Thank you for your reply.
Ubuntu 14.04, an indigo on it with the installed gazebo2 which causes "waiting for namespaces..." (like this http://answers.ros.org/question/19940...)
To avoid that "waiting for namespaces", I turn to new versions of gazebo and tried to install it via http://gazebosim.org/tutorials?tut=in...
got the "unable to locate gazebo7"
These errors are really annoying to me because I am working on a coding and algorithm work and didn't expect such much time (weeks) spent in making existing simulation package work. The main complaint from that I think the project should have the property of downward compatibility. But I cannot see it in Gazebo (and ROS, another rough story..).
Thank you again for your time.
Update
wgt
Resolving packages.osrfoundation.org (packages.osrfoundation.org)... 54.193.183.180
Connecting to packages.osrfoundation.org (packages.osrfoundation.org)|54.193.183.180|:80... connected.
HTTP request sent, awaiting response... 200 OK
Length: 1772 (1.7K) [application/pgp-keys]
Saving to: `STDOUT'
100%[======================================>] 1,772 --.-K/s in 0s
2016-04-02 00:40:00 (154 MB/s) - written to stdout [1772/1772]
sudo apt-get update
Hit http://us.archive.ubuntu.com precise-backports/restricted Translation-en
Hit http://us.archive.ubuntu.com precise-backports/universe Translation-en
Ign http://packages.ros.org precise/main Translation-en_US
Ign http://packages.ros.org precise/main Translation-en
Ign http://packages.osrfoundation.org precise/main Translation-en_US
Ign http://packages.osrfoundation.org precise/main Translation-en
Reading package lists... Done
install gazebo
ubuntu:~$ sudo apt-get install gazebo7
Reading package lists... Done
Building dependency tree
Reading state information... Done
E: Unable to locate package gazebo7
-1. People here are happy to answer specific questions you have -- general complaints are really not constructive. If you have a question on how to do a particular thing: ask. If you have a feature request, make it. If you have a bug report, file it: https://bitbucket.org/osrf/gazebo/issues?status=new&status=open