{"record":{"id":"7f6e2677f791e600","repo":"BloopAI/vibe-kanban","slug":"failed-to-take-child-stderr","errorCode":null,"errorMessage":"Failed to take child stderr","messagePattern":"Failed to take child stderr","errorType":"exception","errorClass":null,"httpStatus":null,"severity":"error","filePath":"crates/embedded-ssh/src/handler.rs","lineNumber":106,"sourceCode":"            cmd.current_dir(home);\n        }\n\n        let mut child = cmd\n            .spawn()\n            .map_err(|e| anyhow::anyhow!(\"Failed to spawn stdio command: {e}\"))?;\n\n        let stdin = child\n            .stdin\n            .take()\n            .ok_or_else(|| anyhow::anyhow!(\"Failed to take child stdin\"))?;\n        let stdout = child\n            .stdout\n            .take()\n            .ok_or_else(|| anyhow::anyhow!(\"Failed to take child stdout\"))?;\n        let stderr = child\n            .stderr\n            .take()\n            .ok_or_else(|| anyhow::anyhow!(\"Failed to take child stderr\"))?;\n\n        let (writer_tx, mut writer_rx) = mpsc::channel::<Vec<u8>>(64);\n        tokio::spawn(async move {\n            let mut stdin = stdin;\n            while let Some(data) = writer_rx.recv().await {\n                if stdin.write_all(&data).await.is_err() {\n                    break;\n                }\n                if stdin.flush().await.is_err() {\n                    break;\n                }\n            }\n        });\n\n        let handle = session.handle();\n        let stdout_task = tokio::spawn(async move {\n            let mut stdout = stdout;\n            let mut buf = vec![0u8; 8192];","sourceCodeStart":88,"sourceCodeEnd":124,"githubUrl":"https://github.com/BloopAI/vibe-kanban/blob/4deb7eca8f381f7cbc1f9d15515a9ab8f8009053/crates/embedded-ssh/src/handler.rs#L88-L124","documentation":"The third take: after spawn, the child's stderr handle must be piped so it can be forwarded to the SSH client. child.stderr.take() returns None when stderr was not set to Stdio::piped(), producing this error. Like the stdin/stdout variants, it signals broken internal command construction rather than a user-triggerable condition.","triggerScenarios":"child.stderr.take() returns None because the command lacks .stderr(Stdio::piped()) at build time in spawn_stdio_session.","commonSituations":"Seen only if the handler's command construction was altered (e.g. stderr inherited for debugging) or partially configured; not triggerable by SSH clients.","solutions":["Ensure .stderr(Stdio::piped()) is set on the command before spawn.","Check that no alternate construction path (e.g. PTY session) reuses this code with different Stdio config.","Test that stderr output from a failing command is visible in the SSH client to confirm piping works."],"exampleFix":"// before\ncmd.stderr(Stdio::null());\n// after\ncmd.stderr(Stdio::piped());","handlingStrategy":"validation","validationCode":"let mut cmd = Command::new(shell);\ncmd.stdin(Stdio::piped());\ncmd.stdout(Stdio::piped());\ncmd.stderr(Stdio::piped()); // required, otherwise take() -> None\nlet mut child = cmd.spawn()?;","typeGuard":null,"tryCatchPattern":null,"preventionTips":["Always pipe stderr for stdio sessions so errors reach the SSH client.","Add a test asserting stderr from a failing command appears on the channel.","Avoid swapping in Stdio::null/inherit for debugging without reverting.","Group all three Stdio settings in one helper to keep them consistent."],"tags":["process-spawn","ssh","invariant-violation"],"backgroundTag":"missing-piped-stdio","analyzedSha":"4deb7eca8f381f7cbc1f9d15515a9ab8f8009053","analyzedAt":"2026-08-29T09:24:13.446Z","schemaVersion":2},"datasetVersion":"2026-08-29T12:17:43.993Z"}