Extensions->Visualize Path->Measure Path (Length) yields error

Windows 10, Inkscape 1.0alpha2 (f2f97a7, 2019-07-12)

measure.py:158: DeprecationWarning: This method will be removed in a future version of Python. Use 'locale.format_string()' instead.
  lenstr = locale.format("%(len)25." + str(prec) + "f", {'len': round(stotal * factor * self.options.scale, prec)}).strip()
Traceback (most recent call last):
  File "measure.py", line 255, in <module>
    Length().run()
  File "C:\APP\Temp\inkscape_devel\share\inkscape\extensions\inkex\base.py", line 88, in run
    self.save_raw(self.effect())
  File "measure.py", line 169, in effect
    tx, ty = cspcofm(p)
  File "C:\APP\Temp\inkscape_devel\share\inkscape\extensions\inkex\bezier.py", line 401, in cspcofm
    area = csparea(csp)
  File "C:\APP\Temp\inkscape_devel\share\inkscape\extensions\inkex\bezier.py", line 376, in csparea
    area += 0.15 * numpy.matmul(numpy.matmul(vec_x, MAT_AREA), vec_y.T)[0, 0]
IndexError: invalid index to scalar variable.