{"record":{"id":"edf33e32517f7f88","repo":"HKUDS/DeepTutor","slug":"page-page-id-references-unknown-chapter-page-ch","errorCode":null,"errorMessage":"Page {page_id} references unknown chapter {page.chapter_id}","messagePattern":"Page (.+?) references unknown chapter (.+?)","errorType":"exception","errorClass":"ValueError","httpStatus":null,"severity":"error","filePath":"deeptutor/book/engine.py","lineNumber":1106,"sourceCode":"        # their hand-built blocks — that would overwrite the deterministic\n        # \"How to read this book\" intro and chapter index with hallucinated\n        # prose. Reaching here means force=True or the page is not yet READY, so\n        # rebuild deterministically (this also refreshes a changed spine).\n        if page.content_type == ContentType.OVERVIEW:\n            page.status = PageStatus.PENDING\n            self.storage.save_page(page)\n            await self._materialize_overview_page(spine, [page], book, stream=stream)\n            page = self.storage.load_page(book_id, page_id) or page\n            await self._maybe_finalize_book(book_id)\n            return page\n\n        if force:\n            self._reset_page_for_force_compile(page)\n            self.storage.save_page(page)\n\n        chapter = spine.chapter_by_id(page.chapter_id)\n        if chapter is None:\n            raise ValueError(f\"Page {page_id} references unknown chapter {page.chapter_id}\")\n\n        bus = stream or get_book_bus(book_id)\n        bstream = BookStream(bus)\n\n        try:\n            async with bstream.stage(STAGE_COMPILATION):\n                page = await self.compiler.compile_page(\n                    book_id=book_id,\n                    chapter=chapter,\n                    page=page,\n                    stream=bstream,\n                    knowledge_bases=book.knowledge_bases,\n                    language=book.language,\n                    depth=book.depth.value,\n                )\n        except Exception as exc:\n            self._mark_page_error(page, exc, prefix=\"Compilation failed\")\n            raise","sourceCodeStart":1088,"sourceCodeEnd":1124,"githubUrl":"https://github.com/HKUDS/DeepTutor/blob/3e82f130422a813cdd73c10b21a44e9325f5821a/deeptutor/book/engine.py#L1088-L1124","documentation":"Error \"Page {page_id} references unknown chapter {page.chapter_id}\" thrown in HKUDS/DeepTutor.","triggerScenarios":"Thrown at deeptutor/book/engine.py:1106 when the library encounters an invalid state.","commonSituations":"See trigger scenarios.","solutions":[],"exampleFix":null,"handlingStrategy":null,"validationCode":null,"typeGuard":null,"tryCatchPattern":null,"preventionTips":[],"tags":[],"backgroundTag":null,"analyzedSha":"3e82f130422a813cdd73c10b21a44e9325f5821a","analyzedAt":"2026-08-27T06:57:25.364Z","schemaVersion":2},"datasetVersion":"2026-08-27T08:17:20.692Z"}