Extruded solid in assemebly to gmsh #30

import assembly_mesh_plugin
from cadquery import Workplane, Assembly

if __name__ == "__main__":
    obj = (Workplane()
           .rect(10, 10)
           .extrude(5)
           )
    obj.faces("-Z").tag("back").end()


    assy = Assembly()
    # main object
    assy.add(obj, name="main")
    # get into gmsh
    gmsh = assy.getTaggedGmsh()
    # tagged face is there
    pg = "main_back"
    print(f"Physical group '{pg}' from tag:")
    dimtags = gmsh.model.getEntitiesForPhysicalName(pg)
    print()
    # clean up physical groups
    gmsh.model.removePhysicalGroups()
    gmsh.model.addPhysicalGroup(dimtags[0][0], [dt[1] for dt in dimtags], name="back")
    # mesh is not extruded
    gmsh.model.mesh.generate(3)
    gmsh.fltk.run()

    # New model with tagged entity only
    # get lines then points
    _, lines = gmsh.model.getAdjacencies(*dimtags[0])
    pts = []
    for l in lines:
        _, pts_ = gmsh.model.getAdjacencies(1, l)
        p1 = gmsh.model.getValue(0, pts_[1], [])
        pts.append(p1)
    # new model
    gmsh.model.add("extruded")

    # rebuild face
    pts_tag = []
    for p in pts:
        pts_tag.append(gmsh.model.occ.addPoint(*p))
    lin_tag = []
    for p0, p1 in zip([pts_tag[-1]]+pts_tag[:-1], pts_tag):
        lin_tag.append(gmsh.model.occ.addLine(p0, p1))
    loop_tag = gmsh.model.occ.addCurveLoop(lin_tag)
    surf_tag = gmsh.model.occ.addPlaneSurface([loop_tag])

    # rebuild physical group
    gmsh.model.addPhysicalGroup(2, [surf_tag], name="back")

    gmsh.model.occ.extrude(
        [[2,surf_tag]],
        dx=0,
        dy=0,
        dz=10,
        numElements=[1],
        recombine=True,
    )
    gmsh.model.occ.synchronize()

    gmsh.model.mesh.generate(3)
    gmsh.fltk.run()

    gmsh.finalize()