Get this error when running roslaunch snakesim snakesim.launch

Get this error when running `roslaunch snakesim snakesim.launch`
```
  File "/Users/alice/mambaforge/envs/ros_env/lib/python3.8/site-packages/numpy/core/function_base.py", line 120, in linspace
    num = operator.index(num)
TypeError: 'float' object cannot be interpreted as an integer
```