rqt_graph GUI not working

Question

Hello,

I am following the steps described in "Understanding ROS Topics" tutorial.

When I try to launch rqt_graph in the console I get this output:

    user@user:~$ rosrun rqt_graph rqt_graph 
Exception AttributeError: AttributeError("'_DummyThread' object has no attribute '_Thread__block'",) in <module 'threading' from '/usr/lib/python2.7/threading.pyc'> ignored

Which I believe is a normal output.

The rqt graph window opens but nothing is shown in it.

I don't know what could be wrong.

Thank you,

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Originally posted by Pino on ROS Answers with karma: 88 on 2013-05-06

Post score: 1

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Original comments

Comment by Pino on 2013-05-06:
Here is a screenshot of what I'm seeing: http://screencloud.net/v/qpXV

Comment by 130s on 2013-05-06:
This screenshot helps more to understand what's happening, and that looks odd. What happens when you run $ rqt from command line and open "Plugins" --> "Graph" on it?

Comment by Pino on 2013-05-06:
This works, now I can see the graph as shown here: http://screencloud.net/v/2bR7 But trying to run it directly using $ rosrun rqt_graph rqt_graph still doesn't work

Comment by 130s on 2013-05-06:
@Pino so if you open rqt_graph via rqt, not directly, do you see nodes & topics or whatever you wanted to see?

Comment by Pino on 2013-06-10:
Yes, opening via rqt solves the problem

Answer 1

AttributeError seems to be python's bug, not ROS, as you might already be aware of.

I just ran that tutorial and have no problem with it. Make sure your terminal you use points to ros master where your nodes running with. It can be verified by commands like:

$ echo $ROS_MASTER_URI 
http://localhost:11311  (you should see this if you're running master on local machine and made no change to port number)

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Update 5/8/13, copying from my comment section) Work around might be to open rqt_graph from rqt's integrated GUI by:

$ rqt 

and open "Plugins" --> "Graph".

In the 2nd snapshot you shared, graph is not yet shown. Do you just forget to take snapshot where graph is shown? Or does the graph not appear yet even though everything else is working correctly (if so that's still a problem. Might be worth opening a ticket on github)?

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Originally posted by 130s with karma: 10937 on 2013-05-06

This answer was ACCEPTED on the original site

Post score: 0

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Original comments

Comment by Pino on 2013-05-06:
Yes, I first believed this was the source of the problem but checked and it's a common error. I did what you suggested and got your same response: $ echo $ROS_MASTER_URI http://localhost:11311