{"record":{"id":"db755f1f7bc0af22","repo":"xai-org/grok-build","slug":"no-timing-events-found-in","errorCode":null,"errorMessage":"no timing events found in {:?}","messagePattern":"no timing events found in (.+?)","errorType":"exception","errorClass":null,"httpStatus":null,"severity":"warning","filePath":"crates/codegen/xai-grok-telemetry/src/instrumentation.rs","lineNumber":494,"sourceCode":"            .unwrap_or(0);\n\n        let trace_event = serde_json::json!({\n            \"name\": name,\n            \"cat\": \"instrumentation\",\n            \"ph\": \"X\",\n            \"ts\": start_us,\n            \"dur\": dur_us,\n            \"pid\": 1,\n            \"tid\": thread_id,\n            \"args\": Value::Object(args),\n        });\n\n        events.push(trace_event);\n        seen += 1;\n    }\n\n    if seen == 0 {\n        return Err(anyhow!(\"no timing events found in {:?}\", input));\n    }\n\n    let trace = serde_json::json!({\n        \"displayTimeUnit\": \"ms\",\n        \"traceEvents\": events,\n    });\n\n    let mut output_file = std::fs::File::create(&output)\n        .map_err(|err| anyhow!(\"failed to create chrome trace {:?}: {}\", output, err))?;\n    serde_json::to_writer_pretty(&mut output_file, &trace)\n        .map_err(|err| anyhow!(\"failed to write chrome trace: {}\", err))?;\n\n    Ok(output)\n}\n\npub fn finalize() -> Result<()> {\n    let mode = mode();\n    if mode == InstrumentationMode::Disabled {","sourceCodeStart":476,"sourceCodeEnd":512,"githubUrl":"https://github.com/xai-org/grok-build/blob/bc7f02eddd3d84085849dc19ed216f11c23b0571/crates/codegen/xai-grok-telemetry/src/instrumentation.rs#L476-L512","documentation":"generate_chrome_trace parses each line of the instrumentation log for timing events; if the whole file yields zero parseable timing events (counter `seen == 0`), it errors because an empty Chrome trace would be useless. This is a validation error, not an I/O error — the file was readable but contained no usable timing data.","triggerScenarios":"Calling generate_chrome_trace against an instrumentation log that is empty, contains only non-timing lines, or whose event format does not match the parser's expected timing-event shape.","commonSituations":"Instrumentation started but no timed operations ran before the trace was generated; the log was rotated/truncated; a version mismatch where the log was written by a different format than the parser expects.","solutions":["Confirm the app actually ran instrumented/timed operations between instrumentation start and log capture","Check the log is non-empty and contains timing records (`wc -l`, inspect first lines)","Regenerate the instrumentation log with the same binary version that parses it","Verify the parser's event-matching logic covers the event types your app emits"],"exampleFix":"// before\nif seen == 0 {\n    return Err(anyhow!(\"no timing events found in {:?}\", input));\n}\n// after\nif seen == 0 {\n    eprintln!(\"warning: no timing events found in {:?}; emitting empty trace\", input);\n}\nlet trace = serde_json::json!({ \"traceEvents\": events });","handlingStrategy":"validation","validationCode":"let has_events = std::fs::read_to_string(&input)?\n    .lines()\n    .any(|l| l.contains(\"\\\"ts\\\"\") || l.contains(\"ph\"));\nif !has_events { eprintln!(\"log contains no timing events; run instrumented workloads first\"); }","typeGuard":null,"tryCatchPattern":"match generate_chrome_trace(opts) {\n    Err(e) if e.to_string().contains(\"no timing events found\") => {\n        eprintln!(\"nothing to trace; ensure instrumented operations ran before generating\");\n    }\n    other => other,\n}","preventionTips":["Run timed/instrumented operations before generating a trace","Check the log is non-empty and expected format before parsing","Keep log writer and trace parser on compatible versions","Detect and warn on truncated/rotated logs"],"tags":["telemetry","instrumentation","empty-data","validation"],"backgroundTag":"no-timing-events-found","analyzedSha":"bc7f02eddd3d84085849dc19ed216f11c23b0571","analyzedAt":"2026-08-31T04:59:42.031Z","schemaVersion":2},"datasetVersion":"2026-08-31T09:17:48.483Z"}