Error when loading urdfs to ROS parameter sever

[james-p-foster]

Hello,

I've recently been working with some of these urdfs alongside ROS. A typical use case of mine when replaying a rosbag is to:

1. Activate roscore and rviz
2. Play the rosbag
3. Add the urdf to the ROS parameter server via: rosparam load <path-to-urdf> robot_description so that I can view the robot urdf in rviz.

On that final third step, rosparam load results in a pyyaml Scanner Error for some of the urdfs. From what I gather, the urdfs are being read as yaml files, and the scanner is failing to read colons followed by whitespace, e.g. :. I believe this is due to the yaml scanner reading the colon and whitespace as indicating a key-value pair (see e.g. here). An example error from anymal_b_simple_description:

yaml.scanner.ScannerError: mapping values are not allowed here
  in "<unicode string>", line 288, column 24:
          <!-- for a sphere: 2/5 m * r**2 -->

I have a fork of this repo with all the offending :s removed from all the robot urdfs. Luckily, these only show up in urdf comments, so no functionality is changed. I can open a PR, if that's desired?

[wxmerkt]

Does rosparam set robot_description -t my_urdf.urdf work?

[james-p-foster]

Awesome stuff -- that works. Thanks for your help! I'll have to educate myself on the differences between rosparam load and rosparam set.

Closing now.