{"record":{"id":"7e8c63b3f87af427","repo":"xai-org/grok-build","slug":"failed-to-create-chrome-trace","errorCode":null,"errorMessage":"failed to create chrome trace {:?}: {}","messagePattern":"failed to create chrome trace (.+?): (.+?)","errorType":"exception","errorClass":null,"httpStatus":null,"severity":"error","filePath":"crates/codegen/xai-grok-telemetry/src/instrumentation.rs","lineNumber":503,"sourceCode":"            \"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 {\n        return Ok(());\n    }\n\n    drop_guard(LOG_GUARD.get());\n    drop_guard(CHROME_GUARD.get());\n\n    Ok(())\n}\n","sourceCodeStart":485,"sourceCodeEnd":521,"githubUrl":"https://github.com/xai-org/grok-build/blob/bc7f02eddd3d84085849dc19ed216f11c23b0571/crates/codegen/xai-grok-telemetry/src/instrumentation.rs#L485-L521","documentation":"generate_chrome_trace writes the assembled trace JSON to the output path (default: input with .trace.json extension). std::fs::File::create failures are wrapped in this message with the output path and OS error text. The subsequent write step has its own separate error (see failed to write chrome trace), so this one specifically means the file could not be created/opened for writing.","triggerScenarios":"Calling generate_chrome_trace where the output path's parent directory does not exist, the path is a directory, or the process lacks write permission — including the default output path derived from the input file.","commonSituations":"Writing to a read-only directory or one owned by another user; output path colliding with an existing directory; disk-full or immutable file; sandboxed environment (CI, container) restricting writes to the chosen location.","solutions":["Check the printed output path's parent directory exists and is writable (`ls -ld`, `touch <file>`)","Pass an explicit options.output to a writable location instead of relying on the input-with-extension default","Fix permissions (`chmod`/`chown`) or run as a user with write access to the target directory","Free disk space or remove an immutable/directory target at the output path"],"exampleFix":"// before\nlet output = options.output.unwrap_or_else(|| input.with_extension(\"trace.json\"));\n// after\nlet output = options.output.unwrap_or_else(|| input.with_extension(\"trace.json\"));\nif let Some(dir) = output.parent() {\n    std::fs::create_dir_all(dir)?;\n}","handlingStrategy":"validation","validationCode":"let output = options.output.unwrap_or_else(|| input.with_extension(\"trace.json\"));\nif let Some(dir) = output.parent() {\n    if !dir.as_os_str().is_empty() && !dir.exists() {\n        std::fs::create_dir_all(dir)?;\n    }\n}\nlet writable = std::fs::OpenOptions::new().write(true).create_new(true).open(&output).is_ok();","typeGuard":"fn writable_target(p: &std::path::Path) -> bool {\n    p.parent().map_or(true, |d| d.is_dir()) && !p.is_dir()\n}","tryCatchPattern":"match generate_chrome_trace(opts) {\n    Err(e) if e.to_string().contains(\"failed to create chrome trace\") => {\n        eprintln!(\"cannot write output: {e}; choose a writable output path\");\n    }\n    other => other,\n}","preventionTips":["Pre-create the output directory before generating traces","Verify write permissions on the output directory in CI/containers","Avoid pointing output at directories or read-only mounts","Check disk free space before large trace exports"],"tags":["io","filesystem","permissions","telemetry"],"backgroundTag":"failed-to-create-file","analyzedSha":"bc7f02eddd3d84085849dc19ed216f11c23b0571","analyzedAt":"2026-08-31T04:59:42.031Z","schemaVersion":2},"datasetVersion":"2026-08-31T09:17:48.483Z"}