Info : BRep contains more volumes than there really are ! Error : HXT 3D mesh failed

Hi All,

I am trying to debug a case where HXT algorithm fails to work while the 3D Delaunay algorithm seems working. I built this debug case gradually. The HXT algorithm works fine when there was no ground extrusion (case with a simple box enclosing the building with boundary layer). But after I added the ground boundary layer, I started getting the following error:

Info    : Meshing volume 14 (Extruded)
Info    : 3D Meshing 1 volume with 1 connected component
Info    : Creating an empty mesh with 1159 vertices
Info    : Initialization of tet. mesh
Info    : Delaunay of       1155 points on   1 threads - mesh.nvert: 4
Info    : Recovering 3 missing facet(s)
Info    : Recover Delaunay
Info    : BRep contains more volumes than there really are !
Error   : HXT 3D mesh failed
Traceback (most recent call last):
  File "20210705_test_debug3.py", line 356, in <module>
    gmsh.model.mesh.generate(3)
  File "C:\Users\anaconda3\lib\site-packages\gmsh-git-Windows64-sdk\lib\gmsh.py", line 1524, in generate
    raise Exception(logger.getLastError())
Exception: HXT 3D mesh failed

20210705_test_debug3.py corner_cut_0.stl

Thanks, Jack