{"record":{"id":"a91c10a917600dd6","repo":"xai-org/grok-build","slug":"failed-to-open-instrumentation-log","errorCode":null,"errorMessage":"failed to open instrumentation log {:?}: {}","messagePattern":"failed to open instrumentation log (.+?): (.+?)","errorType":"exception","errorClass":null,"httpStatus":null,"severity":"error","filePath":"crates/codegen/xai-grok-telemetry/src/instrumentation.rs","lineNumber":403,"sourceCode":"        return Ok(path);\n    }\n    Ok(default_log_path())\n}\n\n#[derive(Debug, Clone, Default)]\npub struct ChromeTraceOptions {\n    pub input: Option<PathBuf>,\n    pub output: Option<PathBuf>,\n}\n\npub fn generate_chrome_trace(options: ChromeTraceOptions) -> Result<PathBuf> {\n    let input = resolve_input_path(options.input)?;\n    let output = options\n        .output\n        .unwrap_or_else(|| input.with_extension(\"trace.json\"));\n\n    let file = std::fs::File::open(&input)\n        .map_err(|err| anyhow!(\"failed to open instrumentation log {:?}: {}\", input, err))?;\n    let reader = io::BufReader::new(file);\n\n    let mut events: Vec<Value> = Vec::new();\n    let mut seen = 0usize;\n\n    for line in reader.lines() {\n        let line = match line {\n            Ok(line) => line,\n            Err(_) => continue,\n        };\n        let value: Value = match serde_json::from_str(&line) {\n            Ok(value) => value,\n            Err(_) => continue,\n        };\n\n        let target = value.get(\"target\").and_then(Value::as_str);\n        if target != Some(TARGET) {\n            continue;","sourceCodeStart":385,"sourceCodeEnd":421,"githubUrl":"https://github.com/xai-org/grok-build/blob/bc7f02eddd3d84085849dc19ed216f11c23b0571/crates/codegen/xai-grok-telemetry/src/instrumentation.rs#L385-L421","documentation":"generate_chrome_trace converts an instrumentation log file into a Chrome trace JSON. It opens the resolved input path with std::fs::File::open and wraps any OS error (not-found, permission denied, is-a-directory, etc.) in this message, which embeds the path and the io::Error text.","triggerScenarios":"Calling generate_chrome_trace with options.input pointing to a path that does not exist, is a directory, or is not readable by the current user after resolve_input_path resolves it.","commonSituations":"Instrumentation was never enabled so the log file was never created; running the trace tool from a different working directory with a relative path; insufficient permissions; wrong file passed via --input.","solutions":["Verify the input path exists: `ls -la <resolved-path>` (the error prints the resolved path)","Enable/check the instrumentation log output that produces the file before tracing","Check file permissions or run as a user with read access","Pass an absolute path to avoid resolve_input_path picking a different directory"],"exampleFix":"// before\nlet input = resolve_input_path(options.input)?;\n// after\nlet input = resolve_input_path(options.input)?;\nif !input.exists() {\n    anyhow::bail!(\"instrumentation log not found at {}; enable instrumentation first\", input.display());\n}","handlingStrategy":"validation","validationCode":"let input = resolve_input_path(options.input)?;\nif !input.is_file() {\n    eprintln!(\"instrumentation log missing at {}\", input.display());\n    return;\n}","typeGuard":"fn readable_file(p: &std::path::Path) -> bool {\n    p.is_file() && std::fs::File::open(p).is_ok()\n}","tryCatchPattern":"match generate_chrome_trace(opts) {\n    Err(e) if e.to_string().contains(\"failed to open instrumentation log\") => {\n        eprintln!(\"log missing/unreadable: {e}; enable instrumentation and rerun\");\n    }\n    other => other,\n}","preventionTips":["Enable instrumentation before attempting trace generation","Use absolute paths for the log input","Check file permissions when running under different users/CI","Confirm the log was not rotated or deleted between runs"],"tags":["io","file-not-found","telemetry","instrumentation"],"backgroundTag":"failed-to-open-file","analyzedSha":"bc7f02eddd3d84085849dc19ed216f11c23b0571","analyzedAt":"2026-08-31T04:59:42.031Z","schemaVersion":2},"datasetVersion":"2026-08-31T09:17:48.483Z"}