stl.py:9: RuntimeWarning: invalid value encountered in true_divide

[FieldsYeh]

from sdf import *

f = sphere(1) & box(1.5)

c = cylinder(0.5) f -= c.orient(X) | c.orient(Y) | c.orient(Z)

f.save('out.stl', step=0.002)

Encounter divide problem when step=0.002 or 0.001