[Bug] Shutdown hangs at user@1000.service/stop for ~90s: dde-session-ctl --shutdown waits forever after transient unit start fails

[liyuan-rey]

问题描述 / Problem

关机/重启时卡在 user@1000.service/stop，需要等待约 90 秒超时后才继续关机。

When shutting down / rebooting, the system hangs at user@1000.service/stop for ~90 seconds until the systemd stop timeout expires.

[  OK  ] Started plymouth-poweroff.service - Show Plymouth Power Off Screen.
[  OK  ] Stopped tailscaled.service - Tailscale node agent.
[    *  ] Job user@1000.service/stop running ...e/stop running (53s / 1min 29s)...

环境 / Environment

项目	值
OS	Deepin 25 (crimson 25.01.01)
内核	6.18.38-amd64-desktop-rolling #25.01.01.28 SMP PREEMPT_DYNAMIC Thu Jul 16 17:57:00 CST 2026 x86_64
dde-session	2.0.29
dde-application-manager	1.2.59
dde-session-shell	6.0.65
dde-session-ui	6.0.46
linglong-bin	1.13.8-1
linglong-box	2.2.1-1
桌面	X11（DDE）
复现日期	2026-08-05 12:46 关机时

日志时间线 / Log timeline (journalctl -b -1)

# 12:46:18 —— 用户会话开始拆解，dde-application-manager 已无法解析应用
8月 05 12:46:18 liyuan-nb dde-application-manager[2399]: dde.am.manager: couldn't find app "bamfdaemon" in application manager.
8月 05 12:46:18 liyuan-nb dde-application-manager[2399]: dde.am.manager: couldn't find app "org.deepin.dde.SoundEffect1" in application manager.

# 12:46:19 —— 关键：dde-session-manager 的 ExecStopPost 触发 dde-session-ctl --shutdown，
# 它请求 dde-application-manager 以 linglong portable binary 方式异步启动 transient unit
8月 05 12:46:19 liyuan-nb dde-application-manager[2399]: Request sent to start transient unit (Async): "app-DDE-tmp.portablebinary.-usr-libexec-dde\\x2dsession\\x2dctl@f801ffb0.service"
8月 05 12:46:19 liyuan-nb dde-application-manager[2399]: dde.am.manager: couldn't find app "dde-session-ctl" in application manager.
8月 05 12:46:19 liyuan-nb dde-application-manager[2399]: dde.am.manager: couldn't find app "home-liyuan" in application manager.

# dde-session-ctl 进程收到了 systemd 的 job 排队确认（job 3557），但 transient unit 实际启动失败，
# 进程不退出，一直挂住
8月 05 12:46:19 liyuan-nb dde-session-ctl[44809]: QDBusMessage(type=MethodReturn, service="", signature="o", contents=([ObjectPath: /org/freedesktop/systemd1/job/3557]) )

# 同一时刻 dde-application-manager 已与 X11 断开，注册实例全面失败
8月 05 12:46:19 liyuan-nb dde-application-manager[2399]: The X11 connection broke (error 1). Did the X11 server die?
8月 05 12:46:19 liyuan-nb dde-application-manager[2399]: dde.am.manager: failed to add instance "/org/freedesktop/systemd1/job/3594" to app "tailscale-systray"
8月 05 12:46:19 liyuan-nb dde-application-manager[2399]: dde.am.manager: failed to add instance "/org/freedesktop/systemd1/job/3596" to app "fcitx5-helper"
8月 05 12:46:19 liyuan-nb dde-application-manager[2399]: dde.am.manager: failed to add instance "/org/freedesktop/systemd1/job/3587" to app "uos-ai-assistant.autostart"

# 12:46:22 —— 三个 DDE 应用 scope 先超时被杀（次要，仅数秒）
8月 05 12:46:22 liyuan-nb systemd[1153]: app-DDE-deepin\x2dwine\x2dbuilder@1106003324d744cd981a160e4dc05838.service: State 'stop-sigterm' timed out. Killing.
8月 05 12:46:22 liyuan-nb systemd[1153]: app-DDE-microsoft\x2dedge@3d27b194ae1f4297811fac7429cb24d8.service: State 'stop-sigterm' timed out. Killing.
8月 05 12:46:22 liyuan-nb systemd[1153]: app-DDE-obsidian@fb2fdd716d4b4002a8725ad5f6f4974c.service: State 'stop-sigterm' timed out. Killing.

# 12:46:29 —— tailscaled 系统服务 stop 超时被杀（断网场景，次要）
8月 05 12:46:29 liyuan-nb systemd[1]: tailscaled.service: State 'stop-sigterm' timed out. Killing.

# 12:47:49 —— ★ 主卡点：dde-session-manager 的 ExecStopPost（dde-session-ctl --shutdown）
# 挂满 90 秒，stop-post 超时被强杀，关机才继续
8月 05 12:47:49 liyuan-nb systemd[1153]: dde-session-manager.service: State 'stop-post' timed out. Terminating.
8月 05 12:47:49 liyuan-nb systemd[1153]: dde-session-manager.service: Control process exited, code=killed, status=15/TERM
8月 05 12:47:49 liyuan-nb systemd[1153]: dde-session-manager.service: Failed with result 'timeout'.

# 附带：OnFailure 接管失败（事务冲突），dde-session-shutdown.target 无法按预期启动
8月 05 12:47:49 liyuan-nb systemd[1153]: dde-session-manager.service: Failed to enqueue OnFailure= job, ignoring: Transaction for dde-session-shutdown.target/start is destructive (gpg-agent-browser.socket has 'stop' job queued, but 'start' is included in transaction).

根因分析 / Root cause analysis

1. dde-session-manager.service（由 dde-session 2.0.29 提供）的 unit 定义：

[Service]
Type=notify
ExecStart=/usr/bin/dde-session --systemd-service
ExecStopPost=/usr/libexec/dde-session-ctl --shutdown

关机时 systemd 停止用户会话，触发 ExecStopPost=/usr/libexec/dde-session-ctl --shutdown。

2. dde-session-ctl --shutdown 的执行路径是：通过 D-Bus 请求 dde-application-manager 以 linglong portable binary 方式异步启动一个 transient unit（app-DDE-tmp.portablebinary.-usr-libexec-dde\x2dsession\x2dctl@f801ffb0.service）来完成会话清理。

3. 但此时 dde-application-manager 已经处于拆解状态（X11 连接已断开、couldn't find app "dde-session-ctl"、注册实例全部失败），transient unit 永远无法真正启动。

4. dde-session-ctl 进程在收到 systemd job 排队确认（job 3557）后没有对启动失败做超时/错误处理，一直等待该 unit 完成，进程永不退出。

5. systemd 等待 ExecStopPost 直到 TimeoutStopSec=90s（用户会话默认），强杀后关机才继续。整个用户会话的停止被这一个进程拖慢 90 秒。

核心问题：dde-session-ctl --shutdown 依赖 dde-application-manager + linglong portable binary 机制执行关机清理，但 dde-application-manager 的停止顺序/状态在关机时无法保证可用，且 dde-session-ctl 对启动失败无超时保护 → 每次关机稳定卡 90 秒。

期望行为 / Expected behavior

• dde-session-ctl --shutdown 应直接执行清理，或对 transient unit 启动失败立即报错退出，不应无超时等待
• 关机时 dde-application-manager 不应早于依赖它的 dde-session-manager 清理流程被拆解（依赖顺序问题）
• 预期关机总耗时与桌面会话大小无关，不应被固定拖慢 90 秒

相关观察 / Related observations（次要）

1. 同一时刻 3 个 app-DDE-* scope（Edge / Obsidian / deepin-wine-builder）stop-sigterm 超时被杀——应用退出不响应 SIGTERM 是另一类问题（Chromium 系 GPU 进程、wine 确认对话框），非本次主因。
2. 关机完成时 systemd[1] 报 Failed unmounting var.mount（/var 为独立分区 /dev/nvme0n1p5，ostree 部署），可能与会话未正常收尾有关，供参考。
3. tailscaled stop 超时被杀系当天网络环境（无外网/断连重连）导致，与本 issue 无关。

附件 / Attachments

完整日志（用户会话 + 系统，2026-08-05 12:44-12:48 时段）：https://gist.github.com/liyuan-rey/2dcf37832e638be337018c2942082026

• user-session.log：journalctl -b -1 --user --since '2026-08-05 12:44:00' --until '2026-08-05 12:47:50'
• system.log：journalctl -b -1 --since '2026-08-05 12:44:00' --until '2026-08-05 12:48:10'