ImportError with raymarching when we launch the training

[BeaverInGreenland]

Hello, when I try to launch this command
python main_nerf.py --config ./configs/scenes/toaster.ini
I run on the following error:

--color_l1_loss no longer used! switch to `--color_loss=l1`
Traceback (most recent call last):
  File "main_nerf.py", line 41, in <module>
    from nerf.network import NeRFNetwork
  File ".../ENVIDR/nerf/network.py", line 7, in <module>
    from .renderer import NeRFRenderer
  File ".../ENVIDR/nerf/renderer.py", line 10, in <module>
    import raymarching
  File ".../ENVIDR/raymarching/__init__.py", line 1, in <module>
    from .raymarching import *
  File ".../ENVIDR/raymarching/raymarching.py", line 10, in <module>
    from raymarching._ext import _raymarching as _backend
ImportError: cannot import name '_raymarching' from 'raymarching._ext' (unknown location)

I set up an environment with python 3.8 and pip installed the requirements.txt file