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RLException: Machine [ubuntu2] already added and does not match duplicate entry

asked 2020-06-12 03:24:00 -0600

magnus gravatar image

updated 2023-06-18 09:56:53 -0600

lucasw gravatar image

I have had a working multi-machine environment for a while but today I get this error that I cannot debug myself.

RLException: Machine [ubuntu2] already added and does not match duplicate entry

I have set the following environment variables:

Machine 1 ubuntu1:

export ROS_IP=

Machine 2 ubuntu2:

export ROS_MASTER_URI=http://localhost:11311
export ROS_IP=

In my launch file, I declare machine like:

<machine name="ubuntu2" address="" env-loader="/home/ubuntu/catkin_ws/src/" user="ubuntu"/>

Machine 2 runs the roscore master node. The namespaces resolves in ssh (ssh ubuntu2). Machine1 runs the launch files. I am not sure what do to fix this.

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I'm not sure whether it's the cause, but in any case: do not set both ROS_HOSTNAME and ROS_IP (and don't set ROS_HOSTNAME to an IP). Use one or the other, in your case you should probably only set ROS_IP.

gvdhoorn gravatar image gvdhoorn  ( 2020-06-12 07:30:52 -0600 )edit

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answered 2020-06-12 09:40:34 -0600

magnus gravatar image

Solution is to check that all startup scripts that call the same <machine> have the same configuration (in my case address).

One small launch file in the launch sequence had an old address, which is why I had duplicate entries which did not match.

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Asked: 2020-06-12 03:24:00 -0600

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Last updated: Jun 12 '20