File "/usr/lib/python3.14/site-packages/docutils/parsers/rst/states.py", line 2286, in run_directive
result = directive_instance.run()
File "/usr/lib/python3.14/site-packages/sphinx/directives/other.py", line 80, in run
self.parse_content(subnode)
~~~~~~~~~~~~~~~~~~^^^^^^^^^
File "/usr/lib/python3.14/site-packages/sphinx/directives/other.py", line 98, in parse_content
all_docnames.remove(current_docname) # remove current document
~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^
KeyError: 'notes/books/index'