panda.launch/ name 'xacro' is not defined ??

[jasser-enbaya]

Hello,
I work with Ubuntu 18.04 (Ros melodic)
I installed Libfranka and franka-ros from this site : https://frankaemika.github.io/docs/index.html
and I didn't face any problem or error. After that, I source my workspace and I want to run the command in the franka_gazebo tutorial, which is :
roslaunch franka_gazebo panda.launch x:=-0.5
world:=$(rospack find franka_gazebo)/world/stone.sdf
controller:=cartesian_impedance_example_controller
rviz:=true

But the launch file don't work, and the output was like that:

---

jesser@jesser-meca:~/catkin_ws$ roslaunch franka_gazebo panda.launch x:=-0.5 world:=$(rospack find franka_gazebo)/world/stone.sdf controller:=cartesian_impedance_example_controller rviz:=true
... logging to /home/jesser/.ros/log/0c46e10e-da90-11ec-b709-3ca067ee1911/roslaunch-jesser-meca-27581.log
Checking log directory for disk usage. This may take a while.
Press Ctrl-C to interrupt
Done checking log file disk usage. Usage is <1GB.

name 'xacro' is not defined
when evaluating expression 'xacro.load_yaml('inertial.yaml')'
when instantiating macro: link_with_sc (/home/jesser/catkin_ws/src/franka_ros/franka_description/robots/utils.xacro)
instantiated from: panda_arm (/home/jesser/catkin_ws/src/franka_ros/franka_description/robots/panda_arm.xacro)
in file: /home/jesser/catkin_ws/src/franka_ros/franka_description/robots/panda_arm.urdf.xacro
RLException: Invalid tag: Cannot load command parameter [robot_description]: command [['xacro', '/home/jesser/catkin_ws/src/franka_ros/franka_description/robots/panda_arm.urdf.xacro', 'gazebo:=true', 'hand:=true', 'arm_id:=panda', 'xyz:=-0.5 0 0', 'rpy:=0 0 0']] returned with code [2].

Param xml is

The traceback for the exception was written to the log file *******************************************************************************************************************************************************

I didn't change anything in files, so please can someone explain this error from me, i searched in internet and i didn't find any prob similar to mine, THX in advance.

[HongminWu]

how to solve this problem?

[Ekanshh]

@HongminWu In franka_description, check your branch. For me, it was on develop and not on melodic-develop. So I did checkout to melodic-devlop. Then I build the workspace again and source it. It worked fine for me afterwards. :)

[yuqiang-yang]

I also met this problem when i was running the panda_moveit_config package. And it seems to be a problem about the xacro version. So i clone the xacro package source into my workspace and remake.

[giorgiapazzi]

I met the same problem. My xacro version is 1.14.6. What should I do?

[Jasser-123]

Thank you all for your responses. I apologize for not being active on this matter.
If I recall correctly, the issue stemmed from the version of the xacro after I executed the sudo apt-get upgrade command. Consequently, I uninstalled it and reinstalled the default version, which resolved all the errors.

So check if you upgrade anything, maybe it's not the xacro it could be franka_description.

[giorgiapazzi]

I solved the problem by cloning the xacro repository directly into my workspace and remake.