{
  "id": "ros2/rosbag2-clock-not-published-when-paused",
  "signature": "[WARN] [rosbag2_player]: No clock publisher. Clock is not being published while playback is paused.",
  "signature_zh": "[警告] [rosbag2_player]: 没有时钟发布者。播放暂停时不会发布时钟。",
  "regex": "\\[WARN\\] \\[rosbag2_player\\]: No clock publisher\\. Clock is not being published while playback is paused\\.",
  "domain": "ros2",
  "category": "runtime_error",
  "subcategory": null,
  "root_cause": "When ros2 bag play is paused (e.g., via spacebar), the /clock topic stops publishing, causing nodes relying on sim_time to hang or fail.",
  "root_cause_type": "generic",
  "root_cause_zh": "当 ros2 bag play 暂停时（例如通过空格键），/clock 主题停止发布，导致依赖 sim_time 的节点挂起或失败。",
  "versions": [
    {
      "version": "ROS2 Humble",
      "introduced": null,
      "deprecated": null,
      "removed": null,
      "behavior_change": null,
      "status": "active"
    },
    {
      "version": "ROS2 Iron",
      "introduced": null,
      "deprecated": null,
      "removed": null,
      "behavior_change": null,
      "status": "active"
    },
    {
      "version": "rosbag2 0.15.x",
      "introduced": null,
      "deprecated": null,
      "removed": null,
      "behavior_change": null,
      "status": "active"
    },
    {
      "version": "rosbag2 0.16.x",
      "introduced": null,
      "deprecated": null,
      "removed": null,
      "behavior_change": null,
      "status": "active"
    }
  ],
  "os_specific": {},
  "dead_ends": [
    {
      "action": "",
      "why_fails": "The bag player controls clock publishing; manual intervention may cause timestamp mismatches or conflicts.",
      "fail_rate": 0.8,
      "condition": "",
      "sources": []
    },
    {
      "action": "",
      "why_fails": "Pausing is intended; restarting loses playback position and may not fix the underlying issue if nodes need continuous clock.",
      "fail_rate": 0.5,
      "condition": "",
      "sources": []
    },
    {
      "action": "",
      "why_fails": "This defeats the purpose of using sim_time and may cause nodes to use wall clock, leading to desynchronization.",
      "fail_rate": 0.9,
      "condition": "",
      "sources": []
    }
  ],
  "workarounds": [
    {
      "action": "Avoid pausing playback. Instead, use 'ros2 bag play --rate 0.0' to freeze time, then resume with a positive rate.",
      "success_rate": 0.85,
      "how": "Avoid pausing playback. Instead, use 'ros2 bag play --rate 0.0' to freeze time, then resume with a positive rate.",
      "condition": "",
      "sources": []
    },
    {
      "action": "Implement a custom clock bridge node that caches the last /clock message and republishes it when the bag is paused.",
      "success_rate": 0.7,
      "how": "Implement a custom clock bridge node that caches the last /clock message and republishes it when the bag is paused.",
      "condition": "",
      "sources": []
    }
  ],
  "workarounds_zh": [
    "避免暂停播放。相反，使用 'ros2 bag play --rate 0.0' 冻结时间，然后以正速率恢复。",
    "实现一个自定义时钟桥接节点，缓存最后一个 /clock 消息，并在包暂停时重新发布它。"
  ],
  "transition_graph": {
    "leads_to": [],
    "preceded_by": [],
    "frequently_confused_with": []
  },
  "official_doc_url": "https://docs.ros.org/en/rolling/Tutorials/Beginner-CLI-Tools/Recording-And-Playing-Back-Data/Recording-And-Playing-Back-Data.html",
  "official_doc_section": null,
  "error_code": null,
  "verification_tier": "ai_generated",
  "confidence": 0.87,
  "fix_success_rate": 0.8,
  "resolvable": "partial",
  "first_seen": "2023-09-10",
  "last_confirmed": "2024-06-01",
  "last_updated": "2024-06-01",
  "evidence_count": 1,
  "tags": [],
  "locale": "en",
  "aliases": []
}