What version of mujoco base do you use?

[husnoo]

git clone https://github.com/BolunDai0216/PyMuJoCoBase.git
cd PyMuJoCoBase
python3 -m pip install .

and edited gymnast.py to use
from PyMuJoCoBase.mujoco_base import MuJoCoBase

error:

Traceback (most recent call last):
  File "/home/nawal/data/software-exercises/mujoco/MuJoCo-Tutorial/examples/gymnast.py", line 100, in <module>
    main()
  File "/home/nawal/data/software-exercises/mujoco/MuJoCo-Tutorial/examples/gymnast.py", line 96, in main
    sim.simulate()
  File "/home/nawal/data/software-exercises/mujoco/MuJoCo-Tutorial/examples/gymnast.py", line 65, in simulate
    mj.mj_step(self.model, self.data)
  File "/home/nawal/data/software-exercises/mujoco/MuJoCo-Tutorial/examples/gymnast.py", line 37, in controller
    J = data.efc_J[:3, :3]
        ~~~~~~~~~~^^^^^^^^
IndexError: too many indices for array: array is 1-dimensional, but 2 were indexed