Traceback (most recent call last):
  File "endurance_line_shading.py", line 344, in <module>
    effect.affect()
  File "/Applications/Inkscape.app/Contents/Resources/share/inkscape/extensions/inkex.py", line 283, in affect
    self.effect()
  File "endurance_line_shading.py", line 334, in effect
    self.draw_path(node, png_temp_file)
  File "endurance_line_shading.py", line 304, in draw_path
    newpath.set('d', simplepath.formatPath(self.drawfunction(image_w, image_h, file)))
  File "endurance_line_shading.py", line 95, in drawfunction
    reader = png.Reader(file)
  File "/Users/romain/.config/inkscape/extensions/png.py", line 1376, in __init__
    self.file = open(kw["filename"], "rb")
IOError: [Errno 2] No such file or directory: '/var/folders/2j/xlshflfs0t373kg51sqcjm_00000gn/T/tmpis3Mqm/LineShading.png'