Error with `--buildings isometric`

[contrapunctus-1]

This error occurs when using the --buildings isometric option. e.g.

map-machine render -i file.osm -s 1920,1080 -z 18 -c ... --buildings isometric --roofs --no-building-colors --overlap 12 -o file.svg

I'm using map-machine v0.1.9 on Debian Testing, installed through pipx -
pipx install git+https://github.com/enzet/map-machine/

Traceback (most recent call last):
  File "/home/contrapunctus/.local/bin/map-machine", line 8, in <module>
    sys.exit(main())
             ~~~~^^
  File "/home/contrapunctus/.local/pipx/venvs/map-machine/lib/python3.13/site-packages/map_machine/main.py", line 44, in main
    mapper.render_map(arguments)
    ~~~~~~~~~~~~~~~~~^^^^^^^^^^^
  File "/home/contrapunctus/.local/pipx/venvs/map-machine/lib/python3.13/site-packages/map_machine/mapper.py", line 395, in render_map
    map_.draw(constructor)
    ~~~~~~~~~^^^^^^^^^^^^^
  File "/home/contrapunctus/.local/pipx/venvs/map-machine/lib/python3.13/site-packages/map_machine/mapper.py", line 99, in draw
    self.draw_buildings(
    ~~~~~~~~~~~~~~~~~~~^
        constructor, self.configuration.use_building_colors
        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    )
    ^
  File "/home/contrapunctus/.local/pipx/venvs/map-machine/lib/python3.13/site-packages/map_machine/mapper.py", line 184, in draw_buildings
    draw_walls(
    ~~~~~~~~~~^
        self.svg,
        ^^^^^^^^^
    ...<5 lines>...
        use_building_colors,
        ^^^^^^^^^^^^^^^^^^^^
    )
    ^
  File "/home/contrapunctus/.local/pipx/venvs/map-machine/lib/python3.13/site-packages/map_machine/feature/building.py", line 239, in draw_walls
    color = Color(
        rgb=(
    ...<3 lines>...
        )
    )
  File "/home/contrapunctus/.local/pipx/venvs/map-machine/lib/python3.13/site-packages/colour.py", line 993, in __init__
    setattr(self, k, v)
    ~~~~~~~^^^^^^^^^^^^
  File "/home/contrapunctus/.local/pipx/venvs/map-machine/lib/python3.13/site-packages/colour.py", line 1006, in __setattr__
    fc(value)
    ~~^^^^^^^
  File "/home/contrapunctus/.local/pipx/venvs/map-machine/lib/python3.13/site-packages/colour.py", line 1055, in set_rgb
    self.hsl = rgb2hsl(value)
               ~~~~~~~^^^^^^^
  File "/home/contrapunctus/.local/pipx/venvs/map-machine/lib/python3.13/site-packages/colour.py", line 437, in rgb2hsl
    raise ValueError("%s must be between 0 and 1. You provided %r."
                     % (name, v))
ValueError: Red must be between 0 and 1. You provided nan.