{
  "id": "go/context-deadline-exceeded-in-select",
  "signature": "error: context deadline exceeded (from select ctx.Done())",
  "signature_zh": "错误：上下文已超过截止时间（来自 select ctx.Done()）",
  "regex": "error:\\ context\\ deadline\\ exceeded\\ \\(from\\ select\\ ctx\\.Done\\(\\)\\)",
  "domain": "go",
  "category": "network_error",
  "subcategory": null,
  "root_cause": "A select statement observes ctx.Done() because the parent context's deadline elapsed. The downstream operation is cancelled, but the caller treats it as a generic error.",
  "root_cause_type": "generic",
  "root_cause_zh": "select 语句观察到 ctx.Done()，因为父上下文的截止时间已到。下游操作被取消，但调用方将其视为通用错误。",
  "versions": [
    {
      "version": "1.7+",
      "introduced": null,
      "deprecated": null,
      "removed": null,
      "behavior_change": null,
      "status": "active"
    }
  ],
  "os_specific": {},
  "dead_ends": [
    {
      "action": "",
      "why_fails": "The deadline is fixed; every retry burns the same expired context and returns instantly.",
      "fail_rate": 0.95,
      "condition": "",
      "sources": []
    },
    {
      "action": "",
      "why_fails": "Callers receive silently wrong results and downstream logic corrupts data.",
      "fail_rate": 0.9,
      "condition": "",
      "sources": []
    }
  ],
  "workarounds": [
    {
      "action": "",
      "success_rate": 0.96,
      "how": "select {\ncase <-ctx.Done():\n    return ctx.Err()\ncase res := <-ch:\n    return res\n}",
      "condition": "",
      "sources": []
    },
    {
      "action": "",
      "success_rate": 0.9,
      "how": "for i := 0; i < 3; i++ {\n    ctx, cancel := context.WithTimeout(parent, 2*time.Second)\n    err := call(ctx)\n    cancel()\n    if err == nil { return nil }\n}",
      "condition": "",
      "sources": []
    }
  ],
  "workarounds_zh": [],
  "transition_graph": {
    "leads_to": [],
    "preceded_by": [],
    "frequently_confused_with": []
  },
  "official_doc_url": null,
  "official_doc_section": null,
  "error_code": null,
  "verification_tier": "ai_generated",
  "confidence": 0.88,
  "fix_success_rate": 0.8,
  "resolvable": "true",
  "first_seen": "2024-08-05",
  "last_confirmed": "2025-01-01",
  "last_updated": "2025-01-01",
  "evidence_count": 0,
  "tags": [],
  "locale": "en",
  "aliases": []
}