Why do I get "cannot marshal None unless allow_none is enabled" error with MoveIt package?
I have generated a MoveIt config package for the Franka Panda robot using the MoveIt setup assistant. However, when trying to do
roslaunch panda_moveit_config demo.launch
I get the error
TypeError: cannot marshal None unless allow_none is enabled
and gives me a little further info:
load_parameters: unable to set parameters (last param was [/move_group/allow_trajectory_execution=True]): cannot marshal None unless allow_none is enabled
Why is this happening? I realize there are some related questions, e.g. this one, but I figure since it's generated from the MoveIt assistant there should be some more specific guidance.
Asked by adamconkey on 2021-01-10 23:24:44 UTC
Answers
EDIT: This has been fixed with this pull request: https://github.com/ros-planning/moveit/pull/2406
I figured this out but thought I'd share since others may have the same issue. The root problem is in the MoveIt setup assistant I did not create any Robot Poses, I skipped that section, and as such the config/fake_controllers.yaml
file has a parameter initial
that then has a blank after it, which gets loaded as None
to the parameter server.
I think the best solution is to simply add at least one Robot Pose (e.g. zero position), then you don't have to worry about this. I suppose alternatively you could delete the initial
parameter being loaded to the server, but there may be a node that needs that, so I would suggest the first option.
Asked by adamconkey on 2021-01-10 23:28:49 UTC
Comments
This sounds like a bug, and would probably be good to report.
I think the best solution is to simply add at least one Robot Pose
The fundamental cause should be addressed, instead of documenting a work-around.
Asked by gvdhoorn on 2021-01-11 03:42:45 UTC
Turns out this has already been addressed a couple months ago: https://github.com/ros-planning/moveit/pull/2406. My guess is it hasn't made its way into the Melodic debian yet as my system is up to date.
Asked by adamconkey on 2021-01-11 12:09:25 UTC
Comments