Assertion error, mesh is None

General
1 
from dolfinx import *
from mpi4py import *

mesh = mesh.create_unit_interval(MPI.COMM_WORLD,8)
V = fem.FunctionSpace(mesh,"Lagrange",2)


print('done')

root@818ab534cb85:~/sandbox# cd /root/sandbox ; /usr/bin/env /bin/python3 /root/.vscode-server/extensions/ms-python.python-2023.12.0/pythonFiles/lib/python/debugpy/adapter/…/…/debugpy/launcher 46521 – /root/sandbox/sandbox.py
Traceback (most recent call last):
File “/root/sandbox/sandbox.py”, line 5, in
V = fem.FunctionSpace(mesh,“Lagrange”,2)
File “/usr/local/dolfinx-real/lib/python3.10/dist-packages/dolfinx/fem/function.py”, line 469, in init
assert mesh is None
AssertionError
root@818ab534cb85:~/sandbox#



Anyone can shed light on why this assertion error. Is that the way things are included on an rc1 docker image for cpp?
2

You should avoid wildcard import while using dolfinx as written here FEniCSx tutorial. So, the code becomes -

from dolfinx import mesh
from dolfinx.fem import FunctionSpace
from mpi4py import MPI

points = [0., 8.]
mesh = mesh.create_interval(MPI.COMM_WORLD,8,points)
V = FunctionSpace(mesh,("CG", 2))

You can use pyvista or paraview to visualize as the mesh as done in the same tutorial I mentioned above FEniCSx tutorial.

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