{"record":{"id":"aade4d160525940f","repo":"HKUDS/DeepTutor","slug":"no-trace-for-that-day","errorCode":null,"errorMessage":"no trace for that day","messagePattern":"no trace for that day","errorType":"http","errorClass":"HTTPException","httpStatus":404,"severity":"warning","filePath":"deeptutor/api/routers/memory.py","lineNumber":717,"sourceCode":"    for path in paths.trace_dir(surf).glob(\"*.jsonl\"):\n        try:\n            path.unlink()\n            removed += 1\n        except OSError:\n            continue\n    return {\"surface\": surf, \"removed_files\": removed}\n\n\n@router.delete(\"/trace/{surface}/day/{day}\")\nasync def clear_trace_day(surface: str, day: str):\n    surf = _validate_surface(surface)\n    try:\n        parsed = date_cls.fromisoformat(day)\n    except ValueError:\n        raise HTTPException(status_code=400, detail=\"day must be YYYY-MM-DD\")\n    path = paths.trace_file(surf, parsed)\n    if not path.exists():\n        raise HTTPException(status_code=404, detail=\"no trace for that day\")\n    try:\n        path.unlink()\n    except OSError as exc:\n        raise HTTPException(status_code=500, detail=str(exc))\n    return {\"surface\": surf, \"day\": day, \"deleted\": True}\n\n\n# ── Snapshot (L1 workspace mirror) ───────────────────────────────────────\n\n\n@router.get(\"/snapshot/{surface}\")\nasync def get_snapshot(surface: str):\n    \"\"\"Return the current entity list for ``surface`` from workspace.\n\n    Snapshot is always derived live from workspace at call time. The response\n    also includes ``pending_changes`` — the diff vs the last persisted state.\n    Refresh commits these pending changes into ``changes.jsonl``.\n    \"\"\"","sourceCodeStart":699,"sourceCodeEnd":735,"githubUrl":"https://github.com/HKUDS/DeepTutor/blob/3e82f130422a813cdd73c10b21a44e9325f5821a/deeptutor/api/routers/memory.py#L699-L735","documentation":"HTTP 404 from DELETE /memory/trace/{surface}/day/{day} when the surface is valid and the date parses, but no trace file exists on disk for that day (paths.trace_file(...).exists() is false). Deletion of an absent trace is treated as not-found rather than a no-op.","triggerScenarios":"Deleting a trace for a day with no recorded activity, a day before traces started being collected, or after the trace was already deleted once.","commonSituations":"Double-invoking the delete endpoint, cleanup cron jobs running over date ranges with gaps, or timezone mismatches where client 'today' differs from the server's trace-file date.","solutions":["Treat 404 as success in idempotent cleanup logic (the end state — no trace file — is achieved)","Check existence via a listing endpoint (if available) before deleting, or just accept 404","Align client/server timezones when computing 'today' so you target the right trace file"],"exampleFix":"// before\nconst res = await fetch(url, {method:'DELETE'});\nif (!res.ok) throw new Error(res.statusText);\n// after\nconst res = await fetch(url, {method:'DELETE'});\nif (res.status === 404) return; // already gone — idempotent\nif (!res.ok) throw new Error(res.statusText);","handlingStrategy":"fallback","validationCode":"// none needed beyond formatting the day; existence check is server-side\nconst day = new Date().toISOString().slice(0, 10);","typeGuard":null,"tryCatchPattern":"try { await clearTraceDay(surface, day); } catch (e) { if (e.status === 404) return; /* idempotent success */ else throw e; }","preventionTips":["Treat 404 on delete as already-deleted success","Align client and server timezones when computing 'today'","Avoid firing deletes for days with no recorded activity"],"tags":["memory","trace","http-404","cleanup","idempotency"],"backgroundTag":"resource-not-found","analyzedSha":"3e82f130422a813cdd73c10b21a44e9325f5821a","analyzedAt":"2026-08-27T06:57:25.364Z","schemaVersion":2},"datasetVersion":"2026-08-27T08:17:20.692Z"}