On launch of robogym servers, pb2 error, TypeError: Descriptors cannot not be created directly.

[kirstyellis]

Hi,

I am trying to use the robogym servers and am running into this issue on launch.

Details of my setup: Ubuntu 20, Ros Noetic, python 3.8.10

The command that I am running that results in the error:

roslaunch ur_robot_server ur_robot_server.launch ur_model:=ur10 gui:=true

The error:

Traceback (most recent call last):
File "/home/kirstyellis/robogym_ws/devel/lib/ur_robot_server/robot_server.py", line 15, in
exec(compile(fh.read(), python_script, 'exec'), context)
File "/home/kirstyellis/robogym_ws/src/robo-gym-robot-servers/ur_robot_server/scripts/robot_server.py", line 5, in
from ur_robot_server.ros_bridge import UrRosBridge
File "/home/kirstyellis/robogym_ws/src/robo-gym-robot-servers/ur_robot_server/src/ur_robot_server/ros_bridge.py", line 12, in
from robo_gym_server_modules.robot_server.grpc_msgs.python import robot_server_pb2
File "/home/kirstyellis/.local/lib/python3.8/site-packages/robo_gym_server_modules/robot_server/grpc_msgs/python/robot_server_pb2.py", line 36, in
_descriptor.FieldDescriptor(
File "/home/kirstyellis/.local/lib/python3.8/site-packages/google/protobuf/descriptor.py", line 560, in new
_message.Message._CheckCalledFromGeneratedFile()
TypeError: Descriptors cannot not be created directly.
If this call came from a _pb2.py file, your generated code is out of date and must be regenerated with protoc >= 3.19.0.
If you cannot immediately regenerate your protos, some other possible workarounds are:

1. Downgrade the protobuf package to 3.20.x or lower.
2. Set PROTOCOL_BUFFERS_PYTHON_IMPLEMENTATION=python (but this will use pure-Python parsing and will be much slower).

Any ideas what is causing this? Has anyone else hit this issue?

Thanks!

[Adarsh3559]

pip install protobuf==3.20

This above command should make it work i guess

[kirstyellis]

Thanks for the suggestion @Adarsh3559, the install instruction for the robogym servers included a command to update protobuf, so I thought maybe downgrading would cause conflict somewhere else. For now it seems OK. Thanks!