Errors in reading .xdmf mesh file and allocating boundary conditions using MPI

[dokken]

@hojin.kim

for facet in wall_facets:
        vertex_indices = connectivity.links(facet)
        wall_vertex_indices.update(vertex_indices)

    wall_vertex_indices = sorted(list(wall_vertex_indices))

    wall_vertex_coords = geometry.x[wall_vertex_indices]

The logic here is not correct. To go from a facet index to the geometry indices, use dolfinx.mesh.entities_to_geometry.
See for instance Extract the coordinates of the boundary points and the value of a function on them - #4 by dokken

I would also suggest trying to visually debug it as done in: Selecting boundary facets to apply traction boundary condition - #2 by dokken