Telemetry / Logging

June 26, 2026 · View on GitHub

The visionOS tools emit structured logs with tracing so each build job can be tracked by job_id. This page summarizes configuration and examples.

RuntimeModeTelemetry

  • Emitted at startup by src/lib/telemetry.rs::RuntimeModeTelemetry.
  • Fields: transport (stdio), config_path (absolute), pending_jobs, instructions, launch_args.
  • Use RUST_LOG=rmcp_sample=info or higher to see JSON/text on stderr (Runbook uses this for startup checks).

Example:

INFO rmcp_sample::runtime: starting MCP server
    transport="stdio" config_path="/Users/example/app/seiro-mcp.toml" pending_jobs=0 instructions="Loaded config /Users/example/app/seiro-mcp.toml; waiting in stdio mode from a local MCP client."

tracing init

  • src/lib/telemetry.rs::init_tracing is called from main; control level with RUST_LOG (default info).
  • Uses EnvFilter, so you can set export RUST_LOG=rmcp_sample=debug,rmcp_sample::visionos=trace to tune per target.
  • MCP clients can pass RUST_LOG via their env section.

About JobSpan

  • JobSpan::start(job_id, job_kind) begins a span under rmcp_sample::visionos.
  • Close with finish(status, exit_code), always recording status (succeeded / failed …) and elapsed_ms.
  • Tool usage:
    • validate_sandbox_policy: emits a validation span; on failure includes SandboxPolicyError code.
    • build_visionos_app: wraps xcodebuild; logs exit_code and artifact_path.
    • fetch_build_output: logs artifact retrieval with job_id / include_logs.

Log examples

2024-05-12T01:23:45.123Z INFO rmcp_sample::visionos{job_id=1ec5c5c4-6bdc-4f42-9d3c-0d24ebc69212 job_kind="build_visionos_app"}: visionOS job completed
    status="succeeded" exit_code=Some(0) elapsed_ms=5123 artifact_zip="target/visionos-builds/1ec5c5c4-6bdc-4f42-9d3c-0d24ebc69212/artifact.zip"

2024-05-12T01:30:02.010Z INFO rmcp_sample::visionos{job_id=de3077d4-1fd5-4a52-89fb-02f6d5c7e5bf job_kind="validate_sandbox_policy"}: visionOS job completed
    status="failed" exit_code=None elapsed_ms=220 code="path_not_allowed"

Operational notes

  • All logs go to stderr; Codex CLI shows them under “logs”. For persistence, set RUST_TRACING_FORMAT=json and redirect to an external logger.
  • tests/integration/visionos_build.rs asserts via the job store, not spans; if you change log format, update this doc and README accordingly.
  • See docs/runbook.md for startup/shutdown exit codes and log checks.

References

  • src/lib/telemetry.rs — init_tracing and JobSpan
  • src/tools/visionos/build.rs — span start/end points
  • src/tools/visionos/artifacts.rs — job success/failure and TTL tracking