TypeError: 'NoneType' object is not subscriptable in computed_values

[zopyx]

WeasyPrint version 55.0 with the HTML/CSS source from https://www.antennahouse.com/xsl-fo-css-comparison gives me this error:

ERROR: Failed to load image at 'file:///Users/ajung/Downloads/xsl-fo-css-comparison-2022%20%281%29/img/typical-box-en.png': URLError: <urlopen error [Errno 2] No such file or directory: '/Users/ajung/Downloads/xsl-fo-css-comparison-2022 (1)/img/typical-box-en.png'>
ERROR: Failed to load image at 'file:///Users/ajung/Downloads/xsl-fo-css-comparison-2022%20%281%29/img/margin-boxes-en.png': URLError: <urlopen error [Errno 2] No such file or directory: '/Users/ajung/Downloads/xsl-fo-css-comparison-2022 (1)/img/margin-boxes-en.png'>
Traceback (most recent call last):
  File "/usr/local/bin/weasyprint", line 8, in <module>
    sys.exit(main())
  File "/opt/weasyprint/lib/python3.10/site-packages/weasyprint/__main__.py", line 182, in main
    html.write_pdf(output, **kwargs)
  File "/opt/weasyprint/lib/python3.10/site-packages/weasyprint/__init__.py", line 177, in write_pdf
    self.render(
  File "/opt/weasyprint/lib/python3.10/site-packages/weasyprint/__init__.py", line 128, in render
    return Document._render(
  File "/opt/weasyprint/lib/python3.10/site-packages/weasyprint/document.py", line 319, in _render
    [Page(page_box) for page_box in page_boxes],
  File "/opt/weasyprint/lib/python3.10/site-packages/weasyprint/document.py", line 319, in <listcomp>
    [Page(page_box) for page_box in page_boxes],
  File "/opt/weasyprint/lib/python3.10/site-packages/weasyprint/layout/__init__.py", line 128, in layout_document
    pages = list(make_all_pages(context, root_box, html, pages))
  File "/opt/weasyprint/lib/python3.10/site-packages/weasyprint/layout/page.py", line 849, in make_all_pages
    page, resume_at = remake_page(i, context, root_box, html)
  File "/opt/weasyprint/lib/python3.10/site-packages/weasyprint/layout/page.py", line 786, in remake_page
    page, resume_at, next_page = make_page(
  File "/opt/weasyprint/lib/python3.10/site-packages/weasyprint/layout/page.py", line 585, in make_page
    root_box, resume_at, next_page, _, _ = block_level_layout(
  File "/opt/weasyprint/lib/python3.10/site-packages/weasyprint/layout/block.py", line 52, in block_level_layout
    return block_level_layout_switch(
  File "/opt/weasyprint/lib/python3.10/site-packages/weasyprint/layout/block.py", line 66, in block_level_layout_switch
    return block_box_layout(
  File "/opt/weasyprint/lib/python3.10/site-packages/weasyprint/layout/block.py", line 108, in block_box_layout
    result = block_container_layout(
  File "/opt/weasyprint/lib/python3.10/site-packages/weasyprint/layout/block.py", line 657, in block_container_layout
    next_page, new_children) = _in_flow_layout(
  File "/opt/weasyprint/lib/python3.10/site-packages/weasyprint/layout/block.py", line 459, in _in_flow_layout
    collapsing_through) = block_level_layout(
  File "/opt/weasyprint/lib/python3.10/site-packages/weasyprint/layout/block.py", line 52, in block_level_layout
    return block_level_layout_switch(
  File "/opt/weasyprint/lib/python3.10/site-packages/weasyprint/layout/block.py", line 66, in block_level_layout_switch
    return block_box_layout(
  File "/opt/weasyprint/lib/python3.10/site-packages/weasyprint/layout/block.py", line 108, in block_box_layout
    result = block_container_layout(
  File "/opt/weasyprint/lib/python3.10/site-packages/weasyprint/layout/block.py", line 657, in block_container_layout
    next_page, new_children) = _in_flow_layout(
  File "/opt/weasyprint/lib/python3.10/site-packages/weasyprint/layout/block.py", line 459, in _in_flow_layout
    collapsing_through) = block_level_layout(
  File "/opt/weasyprint/lib/python3.10/site-packages/weasyprint/layout/block.py", line 52, in block_level_layout
    return block_level_layout_switch(
  File "/opt/weasyprint/lib/python3.10/site-packages/weasyprint/layout/block.py", line 66, in block_level_layout_switch
    return block_box_layout(
  File "/opt/weasyprint/lib/python3.10/site-packages/weasyprint/layout/block.py", line 108, in block_box_layout
    result = block_container_layout(
  File "/opt/weasyprint/lib/python3.10/site-packages/weasyprint/layout/block.py", line 657, in block_container_layout
    next_page, new_children) = _in_flow_layout(
  File "/opt/weasyprint/lib/python3.10/site-packages/weasyprint/layout/block.py", line 459, in _in_flow_layout
    collapsing_through) = block_level_layout(
  File "/opt/weasyprint/lib/python3.10/site-packages/weasyprint/layout/block.py", line 52, in block_level_layout
    return block_level_layout_switch(
  File "/opt/weasyprint/lib/python3.10/site-packages/weasyprint/layout/block.py", line 66, in block_level_layout_switch
    return block_box_layout(
  File "/opt/weasyprint/lib/python3.10/site-packages/weasyprint/layout/block.py", line 108, in block_box_layout
    result = block_container_layout(
  File "/opt/weasyprint/lib/python3.10/site-packages/weasyprint/layout/block.py", line 646, in block_container_layout
    new_footnotes) = _linebox_layout(
  File "/opt/weasyprint/lib/python3.10/site-packages/weasyprint/layout/block.py", line 306, in _linebox_layout
    for i, (line, resume_at) in enumerate(lines_iterator):
  File "/opt/weasyprint/lib/python3.10/site-packages/weasyprint/layout/inline.py", line 38, in iter_line_boxes
    line, resume_at = get_next_linebox(
  File "/opt/weasyprint/lib/python3.10/site-packages/weasyprint/layout/inline.py", line 95, in get_next_linebox
    last_letter, float_width) = split_inline_box(
  File "/opt/weasyprint/lib/python3.10/site-packages/weasyprint/layout/inline.py", line 733, in split_inline_box
    split_inline_level(
  File "/opt/weasyprint/lib/python3.10/site-packages/weasyprint/layout/inline.py", line 468, in split_inline_level
    new_box, skip, preserved_line_break = split_text_box(
  File "/opt/weasyprint/lib/python3.10/site-packages/weasyprint/layout/inline.py", line 904, in split_text_box
    layout, length, resume_index, width, height, baseline = split_first_line(
  File "/opt/weasyprint/lib/python3.10/site-packages/weasyprint/text/line_break.py", line 321, in split_first_line
    layout = create_layout(
  File "/opt/weasyprint/lib/python3.10/site-packages/weasyprint/text/line_break.py", line 258, in create_layout
    layout = Layout(
  File "/opt/weasyprint/lib/python3.10/site-packages/weasyprint/text/line_break.py", line 64, in __init__
    self.setup(context, font_size, style)
  File "/opt/weasyprint/lib/python3.10/site-packages/weasyprint/text/line_break.py", line 98, in setup
    assert not isinstance(style['font_family'], str), (
  File "/opt/weasyprint/lib/python3.10/site-packages/weasyprint/css/__init__.py", line 631, in __missing__
    self[key] = self.parent_style[key]
  File "/opt/weasyprint/lib/python3.10/site-packages/weasyprint/css/__init__.py", line 696, in __missing__
    self[key] = value = self.parent_style[key]
  File "/opt/weasyprint/lib/python3.10/site-packages/weasyprint/css/__init__.py", line 696, in __missing__
    self[key] = value = self.parent_style[key]
  File "/opt/weasyprint/lib/python3.10/site-packages/weasyprint/css/__init__.py", line 696, in __missing__
    self[key] = value = self.parent_style[key]
  File "/opt/weasyprint/lib/python3.10/site-packages/weasyprint/css/__init__.py", line 729, in __missing__
    computed_values.compute_variable(
  File "/opt/weasyprint/lib/python3.10/site-packages/weasyprint/css/computed_values.py", line 213, in compute_variable
    computed_value = _resolve_var(
  File "/opt/weasyprint/lib/python3.10/site-packages/weasyprint/css/computed_values.py", line 174, in _resolve_var
    computed_value = parent_style[new_variable_name] or new_default
TypeError: 'NoneType' object is not subscriptable

[liZe]

Thanks a lot for the bug report. It’s fixed in master and will be included in v56.