{"record":{"id":"15eaab16a41e2e8c","repo":"rtk-ai/rtk","slug":"stderr-streaming-thread-panicked","errorCode":null,"errorMessage":"stderr streaming thread panicked","messagePattern":"stderr streaming thread panicked","errorType":"exception","errorClass":null,"httpStatus":null,"severity":"error","filePath":"src/main.rs","lineNumber":3178,"sourceCode":"                    err.flush()?;\n                }\n\n                Ok(captured)\n            });\n\n            let status = child\n                .0\n                .take()\n                .context(\"Child process missing\")?\n                .wait()\n                .context(format!(\"Failed waiting for command: {}\", cmd_name))?;\n\n            let stdout_bytes = stdout_handle\n                .join()\n                .map_err(|_| anyhow::anyhow!(\"stdout streaming thread panicked\"))??;\n            let stderr_bytes = stderr_handle\n                .join()\n                .map_err(|_| anyhow::anyhow!(\"stderr streaming thread panicked\"))??;\n\n            let stdout = core::utils::decode_process_output(&stdout_bytes);\n            let stderr = core::utils::decode_process_output(&stderr_bytes);\n            let full_output = format!(\"{}{}\", stdout, stderr);\n\n            // Track usage (input = output since no filtering)\n            timer.track(\n                &format!(\"{} {}\", cmd_name, cmd_args.join(\" \")),\n                &format!(\"rtk proxy {} {}\", cmd_name, cmd_args.join(\" \")),\n                &full_output,\n                &full_output,\n            );\n\n            core::utils::exit_code_from_status(&status, &cmd_name)\n        }\n\n        Commands::Trust { list, yes } => {\n            hooks::trust::run_trust(list, yes)?;","sourceCodeStart":3160,"sourceCodeEnd":3196,"githubUrl":"https://github.com/rtk-ai/rtk/blob/0924356b4caba4989607227b7c8824d3d8098719/src/main.rs#L3160-L3196","documentation":"This is the stderr counterpart of the stdout streaming panic: the child's stderr is drained by its own thread, and after `wait()` the JoinHandle is joined at src/main.rs:3178. A panicked stderr reader thread is mapped to `anyhow!(\"stderr streaming thread panicked\")`. The proxied command may have actually completed; the failure is in rtk's internal stderr collection.","triggerScenarios":"The stderr reader thread panics while consuming the child's piped stderr (pipe read error or internal unwrap failure), causing `stderr_handle.join()` to return Err, which main.rs converts into this error after the child has been waited on.","commonSituations":"Very chatty child processes producing huge stderr under memory pressure; child processes that manipulate their own stderr fd; fd-limit exhaustion causing pipe reads to fail inside the thread.","solutions":["Re-run the command — transient pipe/thread failures may not reproduce.","Run the command directly (bypass rtk) to verify the child itself is healthy; if so, file an rtk bug with the repro.","Raise fd/memory limits (`ulimit -n`) if resource exhaustion is suspected.","Upgrade rtk; internal streaming-thread panics are bugs to be fixed in the proxy implementation."],"exampleFix":null,"handlingStrategy":"retry","validationCode":null,"typeGuard":null,"tryCatchPattern":"rtk proxy <cmd> || <cmd>  # rerun directly if rtk's stderr thread panics","preventionTips":["Avoid children that hijack their own stderr fd.","Watch memory/fd limits when streaming very verbose output.","Treat recurrence as an rtk bug: capture the repro command and report it."],"tags":["proxy-mode","thread-panic","stderr","process-piping"],"backgroundTag":"thread-interrupted","analyzedSha":"0924356b4caba4989607227b7c8824d3d8098719","analyzedAt":"2026-09-19T19:25:29.612Z","contentChangedAt":"2026-09-19T19:25:29.612Z","schemaVersion":2},"datasetVersion":"2026-09-23T08:17:48.524Z"}