datawhalechina/hello-agents · error · FileWriteError
无法保存学习计划：{e}
Error message
无法保存学习计划：{e} What it means
FileWriteError raised by FileManager.save_plan when writing the learning plan markdown to BASE_DIR/<domain>/plan.md fails. The original exception (permission denied, missing parent directory, disk full, path is a directory) is interpolated into the message. Note the parent directory is never created by this method, so a domain directory that does not yet exist is the most common cause.
Source
Thrown at Co-creation-projects/Yixiang-Wu-LearningAgent/core/file_manager.py:60
"# 知识总结\n\n> 暂无知识笔记\n", encoding="utf-8"
)
(domain_path / "sessions" / "session_summary.md").write_text(
"# 学习历程\n\n> 暂无学习记录\n", encoding="utf-8"
)
def save_plan(self, domain: str, plan_content: str) -> None:
"""
保存学习计划
Args:
domain: 领域名称
plan_content: 计划内容（markdown格式）
"""
plan_path = self.BASE_DIR / domain / "plan.md"
try:
plan_path.write_text(plan_content, encoding="utf-8")
except Exception as e:
raise FileWriteError(f"无法保存学习计划：{e}")
def save_knowledge(self, domain: str, filename: str, content: str) -> None:
"""
保存知识笔记
Args:
domain: 领域名称
filename: 文件名
content: 文件内容
"""
knowledge_path = self.BASE_DIR / domain / "knowledge" / filename
try:
knowledge_path.write_text(content, encoding="utf-8")
except Exception as e:
raise FileWriteError(f"无法保存知识笔记：{e}")
def save_session(self, domain: str, session_content: str) -> Path:
"""View on GitHub (pinned to 606a07d341)
Solutions
- mkdir the parent before writing: plan_path.parent.mkdir(parents=True, exist_ok=True) inside save_plan
- Sanitize the domain string (strip path separators and whitespace) before building the path
- Check filesystem permissions/ownership of BASE_DIR and the mounted volume in deployment
- Free up disk space or enlarge the volume if ENOSPC
- Include type(e).__name__ and the path in the message so future failures are diagnosable
Example fix
# before
plan_path = self.BASE_DIR / domain / "plan.md"
try:
plan_path.write_text(plan_content, encoding="utf-8")
except Exception as e:
raise FileWriteError(f"无法保存学习计划：{e}")
# after
plan_path = self.BASE_DIR / domain / "plan.md"
try:
plan_path.parent.mkdir(parents=True, exist_ok=True)
plan_path.write_text(plan_content, encoding="utf-8")
except OSError as e:
raise FileWriteError(f"无法保存学习计划 {plan_path}: {type(e).__name__}: {e}") from e Defensive patterns
Strategy: validation
Validate before calling
from pathlib import Path
def can_write_plan(base_dir: Path, domain: str) -> bool:
d = base_dir / domain
if d.exists() and not d.is_dir():
return False
if d.exists():
return os.access(d, os.W_OK)
return os.access(base_dir, os.W_OK) Try / catch
try:
fm.save_plan(domain, content)
except FileWriteError as e:
logger.error("save_plan failed for %s: %s", domain, e)
# surface to user; do not retry without fixing FS Prevention
- Have FileManager guarantee the domain directory tree exists (mkdir parents on every save)
- Treat domain as a sanitized key: strip whitespace, reject '/' and reserved names before any path join
- Run integration tests that save into a tmp_path fixture to catch permission/structure issues in CI
When it happens
Trigger: Calling save_plan(domain, content) when BASE_DIR/<domain> does not exist (write_text does not create parent dirs); running the agent in a read-only container or with insufficient file permissions; BASE_DIR pointing to a path where <domain> collides with an existing file; disk-full or ENOSPC while writing; passing a domain containing path separators or invalid filename characters (e.g. '/', '\0') so the OS rejects the path.
Common situations: First run of a new domain before any directory scaffold was created; deploying to Docker where BASE_DIR is a mounted volume with root ownership; CI runners with read-only workspace; domain string taken from LLM output containing '/' or newline characters.
Related errors
AI-assisted analysis of datawhalechina/hello-agents@606a07d341 (2026-08-14).
Data as JSON: /api/errors/0e3ea1d2446ed2b2.
Report an issue: GitHub.