jinja2.exceptions.UndefinedError: 'mkdocs.theme.Theme object' has no attribute 'logo'

[pawamoy]

Hello, I'm building a gallery of MkDocs themes.

Semantic seems currently broken, here are the logs I'm getting when trying to build a basic site with it:

Traceback (most recent call last):
  File "/media/data/dev/mkdocs-gallery/themes/semantic/.venv/bin/mkdocs", line 8, in <module>
    sys.exit(cli())
             ^^^^^
  File "/media/data/dev/mkdocs-gallery/themes/semantic/.venv/lib/python3.11/site-packages/click/core.py", line 1157, in __call__
    return self.main(*args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/media/data/dev/mkdocs-gallery/themes/semantic/.venv/lib/python3.11/site-packages/click/core.py", line 1078, in main
    rv = self.invoke(ctx)
         ^^^^^^^^^^^^^^^^
  File "/media/data/dev/mkdocs-gallery/themes/semantic/.venv/lib/python3.11/site-packages/click/core.py", line 1688, in invoke
    return _process_result(sub_ctx.command.invoke(sub_ctx))
                           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/media/data/dev/mkdocs-gallery/themes/semantic/.venv/lib/python3.11/site-packages/click/core.py", line 1434, in invoke
    return ctx.invoke(self.callback, **ctx.params)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/media/data/dev/mkdocs-gallery/themes/semantic/.venv/lib/python3.11/site-packages/click/core.py", line 783, in invoke
    return __callback(*args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/media/data/dev/mkdocs-gallery/themes/semantic/.venv/lib/python3.11/site-packages/mkdocs/__main__.py", line 286, in build_command
    build.build(cfg, dirty=not clean)
  File "/media/data/dev/mkdocs-gallery/themes/semantic/.venv/lib/python3.11/site-packages/mkdocs/commands/build.py", line 340, in build
    _build_theme_template(template, env, files, config, nav)
  File "/media/data/dev/mkdocs-gallery/themes/semantic/.venv/lib/python3.11/site-packages/mkdocs/commands/build.py", line 110, in _build_theme_template
    output = _build_template(template_name, template, files, config, nav)
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/media/data/dev/mkdocs-gallery/themes/semantic/.venv/lib/python3.11/site-packages/mkdocs/commands/build.py", line 89, in _build_template
    output = template.render(context)
             ^^^^^^^^^^^^^^^^^^^^^^^^
  File "/media/data/dev/mkdocs-gallery/themes/semantic/.venv/lib/python3.11/site-packages/jinja2/environment.py", line 1301, in render
    self.environment.handle_exception()
  File "/media/data/dev/mkdocs-gallery/themes/semantic/.venv/lib/python3.11/site-packages/jinja2/environment.py", line 936, in handle_exception
    raise rewrite_traceback_stack(source=source)
  File "/media/data/dev/mkdocs-gallery/themes/semantic/.venv/lib/python3.11/site-packages/semantic/404.html", line 1, in top-level template code
    {% extends "base.html" %} {% block content %}
    ^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/media/data/dev/mkdocs-gallery/themes/semantic/.venv/lib/python3.11/site-packages/semantic/base.html", line 59, in top-level template code
    {% block navbar %}
^^^^^^^^^^^^^^^^^^^^^^^
  File "/media/data/dev/mkdocs-gallery/themes/semantic/.venv/lib/python3.11/site-packages/semantic/base.html", line 61, in block 'navbar'
    {%- include "includes/navbar.html" %}
^^^^^^^^^^^^^^^^^^^^^^^
  File "/media/data/dev/mkdocs-gallery/themes/semantic/.venv/lib/python3.11/site-packages/semantic/includes/navbar.html", line 3, in top-level template code
    {%- if config.theme.logo.image %}
^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/media/data/dev/mkdocs-gallery/themes/semantic/.venv/lib/python3.11/site-packages/jinja2/environment.py", line 485, in getattr
    return getattr(obj, attribute)
           ^^^^^^^^^^^^^^^^^^^^^^^
jinja2.exceptions.UndefinedError: 'mkdocs.theme.Theme object' has no attribute 'logo'

Could you take a look and let me know if it needs additional configuration?

Here is an archive containing the docs and configuration:

semantic.tar.gz

tar xvzf semantic.tar.gz
cd semantic
python -m venv .venv
. .venv/bin/activate
pip install mkdocs
pip install $(mkdocs get-deps)
mkdocs build