{"record":{"id":"5d318a2990f6c95c","repo":"chenhg5/cc-connect","slug":"process-tree-pid-d-still-alive-after-sigkill-re","errorCode":null,"errorMessage":"process tree (pid %d) still alive after SIGKILL retries: %w","messagePattern":"process tree \\(pid (.+?)\\) still alive after SIGKILL retries: %w","errorType":"exception","errorClass":null,"httpStatus":null,"severity":"critical","filePath":"agent/claudecode/session.go","lineNumber":1309,"sourceCode":"\t\t\t\"attempt\", attempt, \"max_attempts\", killAttempts, \"error\", killErr)\n\t\tselect {\n\t\tcase <-cs.done:\n\t\t\tslog.Info(\"claudeSession: exited during force-kill retries\")\n\t\t\treturn nil\n\t\tcase <-time.After(2 * time.Second):\n\t\t}\n\t}\n\n\tselect {\n\tcase <-cs.done:\n\t\treturn nil\n\tcase <-time.After(10 * time.Second):\n\t\tpid := -1\n\t\tif cs.cmd != nil && cs.cmd.Process != nil {\n\t\t\tpid = cs.cmd.Process.Pid\n\t\t}\n\t\tif killErr != nil {\n\t\t\treturn fmt.Errorf(\"process tree (pid %d) still alive after SIGKILL retries: %w\", pid, killErr)\n\t\t}\n\t\treturn fmt.Errorf(\"process tree (pid %d) still alive 10s after SIGKILL reported success\", pid)\n\t}\n}\n\n// shellJoinArgs joins args into a single string, quoting any arg that\n// contains whitespace so that a shell-style splitter (like my_cli's\n// splitCommandLine) preserves each arg as one token.\n//\n// Uses single quotes because some splitters (e.g. my_cli) don't support\n// backslash escapes inside double quotes. For values containing single\n// quotes, we close the single-quoted segment, add an escaped single\n// quote, and reopen: 'it'\\”s' → it's\nfunc shellJoinArgs(args []string) string {\n\tvar b strings.Builder\n\tfor i, a := range args {\n\t\tif i > 0 {\n\t\t\tb.WriteByte(' ')","sourceCodeStart":1291,"sourceCodeEnd":1327,"githubUrl":"https://github.com/chenhg5/cc-connect/blob/4000b2338aa6e850c99df54f8b0ed6ed7460b401/agent/claudecode/session.go#L1291-L1327","documentation":"Close attempts a graceful shutdown then SIGKILL of the claude process tree; if the tree is still alive 10 seconds after SIGKILL was reported successful, it returns 'process tree (pid %d) still alive after SIGKILL retries: %w' (wrapping the kill error) or the non-wrapped variant. This signals an orphaned/unkillable process — typically in uninterruptible sleep (D state) or a kill-permission problem.","triggerScenarios":"Close → wait with 10s timeout expires while the process tree (children spawned by claude, e.g. shell tools) survives: process stuck in D state on I/O/NFS, zombie children reparented, kill targeting the wrong pid, or killErr (operation not permitted) from the OS.","commonSituations":"Claude Code spawned shell/tool subprocesses that ignore signals; processes blocked on NFS/FUSE I/O (D state, immune to SIGKILL); container pid-namespace restrictions; runaway sessions accumulating orphaned claude processes.","solutions":["Check process state: `ps -o stat= -p <pid>` — 'D' means uninterruptible I/O; fix the I/O target (unmount/recover NFS) and the process will die","Kill the whole tree manually: `pkill -9 -P <pid>; kill -9 <pid>`, or use cgroup/pid-namespace kill (systemd-run --scope, kill all in cgroup)","Read the wrapped killErr — EPERM means the daemon user lacks permission for that pid (different user/namespace); run cc-connect as the same user or adjust limits","Prevent recurrence: keep claude CLI and its tool subprocesses signal-friendly; consider process-group setup (Setpgid) so Close can kill -PGID"],"exampleFix":"// before\ncmd.SysProcAttr = &syscall.SysProcAttr{} // child may survive in its own group\n// after\ncmd.SysProcAttr = &syscall.SysProcAttr{Setpgid: true}\n// Close: syscall.Kill(-cs.cmd.Process.Pid, syscall.SIGKILL) // kill whole group","handlingStrategy":"retry","validationCode":"// detect unkillable processes early, before Close times out\nfunc processState(pid int) string {\n    b, err := os.ReadFile(fmt.Sprintf(\"/proc/%d/stat\", pid))\n    if err != nil { return \"gone\" }\n    fields := strings.Fields(string(b))\n    if len(fields) > 2 { return fields[2] } // R,S,D,Z,T — 'D' = unkillable I/O wait\n    return \"unknown\"\n}","typeGuard":null,"tryCatchPattern":"if err := sess.Close(); err != nil {\n    if strings.Contains(err.Error(), \"still alive after SIGKILL\") {\n        // extract pid from message or track it; kill whole tree manually\n        exec.Command(\"pkill\", \"-9\", \"-P\", pidStr).Run()\n        exec.Command(\"kill\", \"-9\", pidStr).Run()\n        log.Error(\"orphaned claude process tree\", \"pid\", pidStr)\n    }\n}","preventionTips":["Spawn claude with Setpgid and kill the negative process-group pid so tool subprocesses die too","Avoid running sessions against NFS/FUSE working directories where D-state hangs are common","Run cc-connect and the claude CLI under the same user/namespace so SIGKILL is permitted","Monitor for orphaned claude processes (ps/cgroup accounting) and alert on accumulation"],"tags":["process-lifecycle","sigkill","process-tree","cleanup"],"backgroundTag":"process-kill-failed","analyzedSha":"4000b2338aa6e850c99df54f8b0ed6ed7460b401","analyzedAt":"2026-09-06T11:45:09.575Z","contentChangedAt":"2026-09-06T11:45:09.575Z","schemaVersion":2},"datasetVersion":"2026-09-14T00:17:10.932Z"}