Ask Your Question

xacro: substitution args not supported: No module named 'rospkg'

asked 2019-08-23 05:46:45 -0500

karburettor gravatar image

updated 2019-08-25 06:34:42 -0500

gvdhoorn gravatar image

I am an absolute beginner to Ubuntu and ROS and to such q/a forums, so please be forgiving. I am using Ubuntu 18.04.3 and running ROS Melodic. I am following an old Udacity course archive. It is about a package called simple_arm which I cloned from ( )

I have created my catkin workspace, initialized it, cloned from github, ran catkin_make, sourced bash.setup as according to instructions. However I get an error when run the launch command:

roslaunch simple_arm robot_spawn.launch

The error i receive is:

... logging to /home/karthik/.ros/log/5ae6a64a-c58b-11e9-8b56-34e6ad8bdd6e/roslaunch-UnitedForever-17751.log
Checking log directory for disk usage. This may take awhile.
Press Ctrl-C to interrupt
Done checking log file disk usage. Usage is <1GB.

xacro: in-order processing became default in ROS Melodic. You can drop the option. substitution args not supported:  No module named 'rospkg'
when processing file: /home/karthik/catkin_ws/src/simple_arm/urdf/simple_arm.urdf.xacro
RLException: while processing /home/karthik/catkin_ws/src/simple_arm/launch/robot_description.xml: Invalid <param> tag: Cannot load command parameter [robot_description]: command [/opt/ros/melodic/lib/xacro/xacro --inorder '/home/karthik/catkin_ws/src/simple_arm/urdf/simple_arm.urdf.xacro'] returned with code [2].  Param xml is <param command="$(find xacro)/xacro --inorder '$(find simple_arm)/urdf/simple_arm.urdf.xacro'" name="robot_description"/> The traceback for the exception was written to the log file 
edit retag flag offensive close merge delete


Did you change anything from the code? I just cloned the repo and it works for me...

ffusco gravatar imageffusco ( 2019-08-23 09:35:59 -0500 )edit

2 Answers

Sort by ยป oldest newest most voted

answered 2019-08-25 06:12:02 -0500

karburettor gravatar image

I had installed Anaconda. It had changed some python path. Uninstalling it and running above code solved the error. Thanks.

edit flag offensive delete link more

answered 2019-08-23 11:03:53 -0500

Just wanting to make sure, you do have rospkg installed, right?

sudo apt-get install python-rospkg

edit flag offensive delete link more


Yes. Sorry for not mentioning.

karburettor gravatar imagekarburettor ( 2019-08-25 06:08:35 -0500 )edit

Your Answer

Please start posting anonymously - your entry will be published after you log in or create a new account.

Add Answer

Question Tools

1 follower


Asked: 2019-08-23 05:43:26 -0500

Seen: 47 times

Last updated: Aug 25