openai_ros turtlebot2 example, setup, documentation, UnboundLocalError: 'linear_speed', noetic, melodic, kinetic, ubuntu 20.04, ubuntu 16.04

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Hello all,

For anyone trying to run the turtlebot2 example today, I am providing links to threads below that will help you because it is so hard to find out how to make this ROS package work with ROS Noetic + Ubuntu 20.04.

THE CURRENT WIKI ROS PAGE DOES NOT WORK WITH ROS NOETIC AND UBUNTU 20.04

I am running the turtlebot2 example from openai_ros on ROS Development Studio from the Construct with ROS Kinetic, because the examples don't seem to be updated for ROS Noetic (I don't think they are currently supported).

I am currently running into an error when the turtlebot is trying to do action 3.

From the code: Line 125, VSCode gives me an error message

"bad operand type for unary -: _Unspecified pylint(invalid-unary-operand-type)"

  linear_speed = -self.linear_turn_speed

And the error message points to

Line 131

    self.move_base(linear_speed, angular_speed, epsilon=0.05, update_rate=10)

This is not the full terminal output but most of it:

[WARN] [1650843499.233519, 1801.370000]: Next action is:3
Traceback (most recent call last):
  File "/home/user/catkin_ws/src/openai_examples_projects/turtle2_openai_ros_example/scripts/start_qlearning.py", line 74, in <module>
    observation, reward, done, info = env.step(action)
  File "/usr/local/lib/python2.7/dist-packages/gym/core.py", line 103, in step
    return self._step(action)
  File "/usr/local/lib/python2.7/dist-packages/gym/wrappers/monitoring.py", line 33, in _step
    observation, reward, done, info = self.env.step(action)
  File "/usr/local/lib/python2.7/dist-packages/gym/core.py", line 103, in step
    return self._step(action)
  File "/usr/local/lib/python2.7/dist-packages/gym/wrappers/time_limit.py", line 36, in _step
    observation, reward, done, info = self.env.step(action)
  File "/home/simulations/public_sim_ws/src/all/openai_ros/openai_ros/src/openai_ros/robot_gazebo_env.py", line 48, in step
    self._set_action(action)
  File "/home/user/catkin_ws/src/openai_examples_projects/turtle2_openai_ros_example/scripts/turtlebot2/turtlebot2_maze.py", line 162, in _set_action
    self.move_base(linear_speed,
UnboundLocalError: local variable 'linear_speed' referenced before assignment

Will update this thread with a fix if I am able to find one.

Thanks.

Some extra context:

I receive these warning messages when I run

roslaunch gym_construct main.launch

Warnings:

[Wrn] [Publisher.cc:141] Queue limit reached for topic /gazebo/default/pose/local/info, deleting message. This warning is printed only once.
[Wrn] [msgs.cc:1808] Conversion of sensor type[depth] not suppported.
[Wrn] [msgs.cc:1808] Conversion of sensor type[imu] not suppported.
[Wrn] [msgs.cc:1808] Conversion of sensor type[gpu_ray] not suppported.
[Wrn] [msgs.cc:1808] Conversion of sensor type[depth] not suppported.
[Wrn] [msgs.cc:1808] Conversion of sensor type[imu] not suppported.
[Wrn] [msgs.cc:1808] Conversion of sensor type[gpu_ray] not suppported.