{"record":{"id":"dfe82586286472cd","repo":"datawhalechina/hello-agents","slug":"e-dfe825","errorCode":null,"errorMessage":"无法保存知识笔记：{e}","messagePattern":"无法保存知识笔记：(.+?)","errorType":"exception","errorClass":"FileWriteError","httpStatus":null,"severity":"error","filePath":"Co-creation-projects/Yixiang-Wu-LearningAgent/core/file_manager.py","lineNumber":75,"sourceCode":"        try:\n            plan_path.write_text(plan_content, encoding=\"utf-8\")\n        except Exception as e:\n            raise FileWriteError(f\"无法保存学习计划：{e}\")\n\n    def save_knowledge(self, domain: str, filename: str, content: str) -> None:\n        \"\"\"\n        保存知识笔记\n\n        Args:\n            domain: 领域名称\n            filename: 文件名\n            content: 文件内容\n        \"\"\"\n        knowledge_path = self.BASE_DIR / domain / \"knowledge\" / filename\n        try:\n            knowledge_path.write_text(content, encoding=\"utf-8\")\n        except Exception as e:\n            raise FileWriteError(f\"无法保存知识笔记：{e}\")\n\n    def save_session(self, domain: str, session_content: str) -> Path:\n        \"\"\"\n        保存单次学习会话记录\n\n        Args:\n            domain: 领域名称\n            session_content: 会话内容\n\n        Returns:\n            保存的文件路径\n        \"\"\"\n        date = datetime.now().strftime(\"%Y-%m-%d\")\n        time = datetime.now().strftime(\"%H-%M\")\n        session_path = self.BASE_DIR / domain / \"sessions\" / f\"session_{date}_{time}.md\"\n\n        try:\n            session_path.write_text(session_content, encoding=\"utf-8\")","sourceCodeStart":57,"sourceCodeEnd":93,"githubUrl":"https://github.com/datawhalechina/hello-agents/blob/606a07d341a47be773fab7f4b71177f53f96b2c3/Co-creation-projects/Yixiang-Wu-LearningAgent/core/file_manager.py#L57-L93","documentation":"FileWriteError raised by FileManager.save_knowledge when writing a knowledge note to BASE_DIR/<domain>/knowledge/<filename> fails. write_text does not create intermediate directories, so a missing knowledge/ subdirectory is the dominant trigger. The bare except Exception also swallows the traceback unless re-raised with `from e`.","triggerScenarios":"Calling save_knowledge before BASE_DIR/<domain>/knowledge/ exists; filename containing '/' causing an unexpected nested path or escape outside knowledge/; permission errors on the knowledge directory; filename being empty or '.' so the path resolves to a directory; disk full.","commonSituations":"Agent writes its first note for a newly created domain that only has plan.md; LLM-generated filename with slashes or Windows-style separators; read-only mount in production.","solutions":["mkdir the knowledge dir first: knowledge_path.parent.mkdir(parents=True, exist_ok=True)","Validate filename: reject empty strings, '/' and '..' components to prevent path traversal","Fix directory permissions/ownership on BASE_DIR and descendants","Chain the original exception with `raise ... from e` to preserve the traceback"],"exampleFix":"# before\nknowledge_path = self.BASE_DIR / domain / \"knowledge\" / filename\ntry:\n    knowledge_path.write_text(content, encoding=\"utf-8\")\nexcept Exception as e:\n    raise FileWriteError(f\"无法保存知识笔记：{e}\")\n\n# after\nif not filename or '/' in filename or filename in {'.', '..'}:\n    raise ValueError(f\"非法笔记文件名: {filename!r}\")\nknowledge_path = self.BASE_DIR / domain / \"knowledge\" / filename\ntry:\n    knowledge_path.parent.mkdir(parents=True, exist_ok=True)\n    knowledge_path.write_text(content, encoding=\"utf-8\")\nexcept OSError as e:\n    raise FileWriteError(f\"无法保存知识笔记 {knowledge_path}: {e}\") from e","handlingStrategy":"validation","validationCode":"import re\n\nSAFE_FILENAME = re.compile(r\"^[\\w\\-]+\\.(md|txt)$\")\n\ndef valid_knowledge_filename(filename: str) -> bool:\n    return bool(filename) and bool(SAFE_FILENAME.match(filename))","typeGuard":"def is_safe_filename(name: str) -> bool:\n    return (\n        isinstance(name, str)\n        and name not in ('.', '..')\n        and '/' not in name\n        and '\\\\' not in name\n        and name.strip() != ''\n    )","tryCatchPattern":"try:\n    fm.save_knowledge(domain, filename, content)\nexcept FileWriteError as e:\n    logger.error(\"knowledge save failed: %s/%s: %s\", domain, filename, e)","preventionTips":["Whitelist filename patterns (markdown extensions only) before calling save_knowledge","Never pass LLM-generated filenames through unchecked — sanitize or derive them from a slug + timestamp","Create knowledge/ at domain initialization time, not lazily at first write"],"tags":["filesystem","io","python","path-traversal","learning-agent"],"backgroundTag":null,"analyzedSha":"606a07d341a47be773fab7f4b71177f53f96b2c3","analyzedAt":"2026-08-14T22:57:27.446Z","schemaVersion":2},"datasetVersion":"2026-08-15T22:17:37.221Z"}