Package: python3-meshplex Followup-For: Bug #1094984 Control: tags -1 ftbfs Control: block -1 by 1094985
The bug is effectively in meshio, meshplex is simply accessing a mesh returned by meshio. The problem is that the 2D cell type ("triangle") has no dtype attached to the cell array. Evidently in numpy 2 this defaults to dtype float, even if the values are integers. By constant the 3D cell type ("tetrahedron") extracted from the same mesh comes with dtype=int64. In meshio source where get_cells_type is defined, a default dtype=int is used for empty cell lists. I think the failing meshplex test is using this for tetra. The test mesh is 2D, and the test checks if the list is empty. I'm not where exactly meshio is setting up the cell list (with no explicit dtype). numpy 2 bug reports have already been filed against meshio (Bug#1094985, https://github.com/nschloe/meshio/issues/1499 )