Book Parts Cannot Be Nested
project
A
part: entry inside another part’s chapters: list is not supported.
Q-5-34 — Book parts cannot be nested
A
part:entry inside another part’schapters:list is not supported.
What this means
Book structure is two levels deep: book.chapters (and
book.appendices) list chapters, and a part: entry groups a run of
chapters under a divider. A part cannot itself contain another part —
Quarto 1’s book model has no nested-part concept, so Quarto 2 rejects
the shape rather than silently flattening or mis-rendering it.
Why this happens
- An indentation mistake in
_quarto.yml— a part entry indented one level too deep, landing inside the previous part’schapters:. - A genuinely nested outline — parts within parts — which book projects do not support.
How to fix
Move the nested part to the top level of book.chapters:
book:
chapters:
- index.qmd
- part: "Part I"
chapters:
- intro.qmd
- part: "Part II" # top level, not inside Part I's chapters
chapters:
- advanced.qmdIf you need deeper structure within a part, use ordinary headings inside the chapters themselves.