ValueError: Null TopoDS_Shape object with offset of circle

[louisabraham]

ellipsis_big = 1
ellipsis_small = 1
s = cq.Sketch().ellipse(ellipsis_big, ellipsis_small).wires().offset(-0.1, mode="s")

Any value of ellipsis_small different than 1 will not cause a bug. Using circle or ellipsis_small = ellipsis_big causes ValueError: Null TopoDS_Shape object. Currently I use 0.999 to alleviate the issue.

[adam-urbanczyk]

Confirmed, FWIW a workaround:

import cadquery as cq

from cadquery.func import wire, ellipse
from math import pi

eps = 1e-6

s = cq.Sketch().face(wire(ellipse(1,1).trim(0,2*pi-eps)).wires().offset(-0.1, mode='s')