Arabic build fails because of KeyError: 'uniFBB6'

[marekjez86]

File "/opt/hostedtoolcache/Python/3.8.3/x64/lib/python3.8/site-packages/fontmake/font_project.py", line 165, in build_master_ufos
designspace = glyphsLib.to_designspace(
File "/opt/hostedtoolcache/Python/3.8.3/x64/lib/python3.8/site-packages/glyphsLib/builder/init.py", line 111, in to_designspace
return builder.designspace
File "/opt/hostedtoolcache/Python/3.8.3/x64/lib/python3.8/site-packages/glyphsLib/builder/builders.py", line 277, in designspace
list(self.masters) # Make sure that the UFOs are built
File "/opt/hostedtoolcache/Python/3.8.3/x64/lib/python3.8/site-packages/glyphsLib/builder/builders.py", line 199, in masters
self.to_ufo_glyph(ufo_glyph, layer, glyph)
File "/opt/hostedtoolcache/Python/3.8.3/x64/lib/python3.8/site-packages/glyphsLib/builder/glyph.py", line 131, in to_ufo_glyph
self.to_ufo_glyph_background(ufo_glyph, layer)
File "/opt/hostedtoolcache/Python/3.8.3/x64/lib/python3.8/site-packages/glyphsLib/builder/glyph.py", line 277, in to_ufo_glyph_background
self.to_ufo_components(new_glyph, background)
File "/opt/hostedtoolcache/Python/3.8.3/x64/lib/python3.8/site-packages/glyphsLib/builder/components.py", line 44, in to_ufo_components
to_ufo_components_background_decompose(self, ufo_glyph, layer)
File "/opt/hostedtoolcache/Python/3.8.3/x64/lib/python3.8/site-packages/glyphsLib/builder/components.py", line 112, in to_ufo_components_background_decompose
component.draw(rpen)
File "/opt/hostedtoolcache/Python/3.8.3/x64/lib/python3.8/site-packages/glyphsLib/classes.py", line 2267, in draw
pen.addComponent(self.name, self.transform)
File "/opt/hostedtoolcache/Python/3.8.3/x64/lib/python3.8/site-packages/fontTools/pens/basePen.py", line 176, in addComponent
glyph = self.glyphSet[glyphName]
KeyError: 'uniFBB6'