I ran into an issue while doing "Understanding ROS Nodes" tutorial
http://www.ros.org/wiki/ROS/Tutorials/UnderstandingTopics#preview
I noticed that killed ROS nodes are not being removed from "rosnode list".
When I used "rosnode info turtlesim", I saw:
...
contacting node
http://i7:*56977*/ ...
ERROR: Communication with node[
http://i7:56977/] failed!
I thought maybe it was because I did not have $ROS_HOSTNAME defined as
described here:
http://www.ros.org/wiki/ROS/NetworkSetup#Single_machine_configuration
So I added export ROS_HOSTNAME=localhost
After that "rosnode info turtlesim" give me:
...
contacting node
http://localhost:*60372*/ ...
Pid: 6178
I thought it was strange to see a different port number, but rosnode list
started working.
Then I went to the next tutorial and did "roscore" while other roscore was
running.
Then I noticed that "rosnode list" again doesn't work and "rosnode info
turtlesim" now gives:
contacting node
http://localhost:39889/ ...
ERROR: Communication with node[
http://localhost:39889/] failed!
P.S. I'm using Fuerte with a fresh Ubuntu-12.04, 64-bit.