Export fails: "style" -- TypeError: this element does not have children or attributes

[tilusnet]

Traceback (most recent call last): File "synfig_output.py", line 1344, in e.affect(output=False) File "/usr/share/inkscape/extensions/inkex.py", line 215, in affect self.effect() File "synfig_output.py", line 1053, in effect SynfigPrep.effect(self) File "/home/tilushq/.config/inkscape/extensions/synfig_prepare.py", line 484, in effect propagate_attribs(self.document.getroot()) File "/home/tilushq/.config/inkscape/extensions/synfig_prepare.py", line 432, in propagate_attribs propagate_attribs(c, this_style, this_transform) File "/home/tilushq/.config/inkscape/extensions/synfig_prepare.py", line 440, in propagate_attribs node.set("style", simplestyle.formatStyle(this_style)) File "lxml.etree.pyx", line 1548, in lxml.etree.__ContentOnlyElement.set (src/lxml/lxml.etree.c:51108) File "lxml.etree.pyx", line 1544, in lxml.etree.__ContentOnlyElement._raiseImmutable (src/lxml/lxml.etree.c:51004) TypeError: this element does not have children or attributes

[nikitakit]

Could you provide a sample SVG file that causes this issue?

[MU-Software]

I can make same issue using this svg file.
black_rightpointing_triangle.zip