AxisError: axis 1 is out of bounds for array of dimension 1

[sugizo]

env
google colab

steps

pip install -U pymartini trimesh
!wget -c https://raw.githubusercontent.com/kylebarron/pymartini/master/test/data/fuji.png

code

import imageio.v2 as imageio
from pymartini import decode_ele, Martini, rescale_positions
import trimesh

path = './fuji.png'
fuji = imageio.imread(path)
terrain = decode_ele(fuji, 'mapbox')
martini = Martini(fuji.shape[0] + 1)
tile = martini.create_tile(terrain)
vertices, triangles = tile.get_mesh(10)
mesh = trimesh.Trimesh(vertices = vertices,
                       faces = triangles,
                       process = False)
mesh.export(f'{file_name}_trimesh.stl')

result

AxisError                                 Traceback (most recent call last)
[<ipython-input-12-8a314949ac13>](https://localhost:8080/#) in <cell line: 14>()
     12                        faces = triangles,
     13                        process = False)
---> 14 mesh.export(f'{file_name}_trimesh.stl')

7 frames
[/usr/local/lib/python3.10/dist-packages/numpy/lib/function_base.py](https://localhost:8080/#) in diff(a, n, axis, prepend, append)
   1417     if nd == 0:
   1418         raise ValueError("diff requires input that is at least one dimensional")
-> 1419     axis = normalize_axis_index(axis, nd)
   1420 
   1421     combined = []

AxisError: axis 1 is out of bounds for array of dimension 1

n.b.
the same steps work fine with pydelatin

best regards