Function revolved_cone_on_box 

pub fn revolved_cone_on_box() -> Program

A box with a round hole through it, and a triangle sketched on its side face, revolved around one of its own edges and joined to the box: a double cone whose axis lies in the side face, so that both apexes sit on it and half the cone stands out of the box.

Reproduces a real user bug report (2026-09-30) with the exact reported coordinates and sketch ids: the revolve1 union failed in remesh_edges_x_faces with “the spokes … are not coplanar: an apex has no single normal” from NurbSurface::pole_normal: trace_one_side asked for the cone’s normal at its apex, to find which way a curve leaves it.