{"record":{"id":"49d12c7fbb8a1249","repo":"Hmbown/CodeWhale","slug":"tmux-session-session-remains-active-after-kill-s","errorCode":null,"errorMessage":"tmux session {session} remains active after kill-session ({status})","messagePattern":"tmux session (.+?) remains active after kill-session \\((.+?)\\)","errorType":"exception","errorClass":null,"httpStatus":null,"severity":"error","filePath":"crates/lane/src/runtime.rs","lineNumber":610,"sourceCode":"    )\n}\n\nfn stop_tmux_session(socket: &Path, session: &str) -> Result<()> {\n    let status = tmux_command(socket)\n        .args([\"kill-session\", \"-t\", session])\n        .stdout(Stdio::null())\n        .stderr(Stdio::null())\n        .status()\n        .with_context(|| format!(\"kill tmux session {session}\"))?;\n    match tmux_session_state(socket, session).with_context(|| {\n        format!(\n            \"confirm tmux session {session} on {} stopped after kill-session ({status})\",\n            socket.display()\n        )\n    })? {\n        TmuxSessionState::Absent => {}\n        TmuxSessionState::Present => {\n            bail!(\"tmux session {session} remains active after kill-session ({status})\")\n        }\n    }\n    // A nonzero kill can be benign when the process and session exited in the\n    // same instant. The explicit absence check above is the source of truth.\n    Ok(())\n}\n\nfn tmux_log_proxy_command(\n    proxy: &Path,\n    command: &[String],\n    log_path: &Path,\n    receipt_path: &Path,\n    receipt_tmp_path: &Path,\n    environment_path: Option<&Path>,\n    lane_id: &str,\n) -> String {\n    let mut argv = vec![\n        proxy.display().to_string(),","sourceCodeStart":592,"sourceCodeEnd":628,"githubUrl":"https://github.com/Hmbown/CodeWhale/blob/73e0f67d83c59909b571efdfc88c4bc28c309cb1/crates/lane/src/runtime.rs#L592-L628","documentation":"After `stop_tmux_session` sends `tmux kill-session`, it re-checks the session state via `tmux_session_state`. If the session is still Present, the kill did not take effect and the runtime refuses to claim the lane stopped — a Running record would otherwise lie about a live process. The accompanying comment notes a nonzero kill exit can be benign when process and session exit simultaneously; the explicit absence check, not the kill exit code, is the source of truth.","triggerScenarios":"Calling `start` or `stop` on a tmux lane when `kill-session` reports success (or is tolerated as benign-failure) but the follow-up `has-session` still finds the session — e.g. tmux respawned the session via `remain-on-exit`, another client recreated it, or the kill targeted a different socket than the one queried.","commonSituations":"A tmux hook or `remain-on-exit on` in the server config keeps the session object alive; a supervisor script inside the session restarts it; concurrent tooling re-attaches and recreates the session between kill and check; a pinned tmux_socket mismatch in the lane record makes kill and check hit different servers.","solutions":["Check tmux server options for `remain-on-exit` or respawn hooks: `tmux -S <socket> show-options -g remain-on-exit` and disable them.","Verify no supervisor inside the session (e.g. a wrapper script loop) restarts the pane command; kill the underlying processes instead.","Confirm the lane record's pinned tmux_socket matches the socket actually used to kill the session.","As a last resort, kill the whole tmux server for that socket (`tmux -S <socket> kill-server`) and then reconcile the lane."],"exampleFix":"// before (session persists due to remain-on-exit)\n$ tmux -S /tmp/lane.sock set -g remain-on-exit on\n\n// after\n$ tmux -S /tmp/lane.sock set -g remain-on-exit off","handlingStrategy":"retry","validationCode":"// after kill-session, verify absence before proceeding\nlet state = tmux_session_state(socket, session)?;\nif matches!(state, TmuxSessionState::Present) {\n    eprintln!(\"session still present; check remain-on-exit and respawn hooks\");\n}","typeGuard":null,"tryCatchPattern":null,"preventionTips":["Keep `remain-on-exit off` on servers hosting lane sessions.","Avoid supervisor loops inside lane session commands.","Ensure the record's pinned socket matches the socket used at start."],"tags":["tmux","lifecycle","process"],"backgroundTag":"invalid-state-transition","analyzedSha":"73e0f67d83c59909b571efdfc88c4bc28c309cb1","analyzedAt":"2026-09-22T01:30:00.501Z","contentChangedAt":"2026-09-22T01:30:00.501Z","schemaVersion":2},"datasetVersion":"2026-09-23T08:17:48.524Z"}