Decision Trace Export

Renacer captures transpiler decision traces and exports them to entrenar's CITL (Compiler-in-the-Loop) oracle for pattern learning.

Overview

When tracing transpiled binaries, renacer captures:

• Type mapping decisions (Python type → Rust type)
• Borrow strategy decisions (owned vs borrowed)
• Lifetime inference decisions
• Unsafe block placement decisions

These decision traces feed entrenar's pattern store, enabling cost-free error fixing over time.

Configuration

TOML Configuration

# ~/.config/renacer/decision_export.toml

otlp_endpoint = "http://localhost:4317"
batch_size = 100
flush_interval_ms = 1000
queue_size = 10000

[retry]
max_attempts = 5
initial_backoff_ms = 100
max_backoff_ms = 30000

Environment Variables

export RENACER_OTLP_ENDPOINT="http://entrenar.example.com:4317"
export RENACER_AUTH_TOKEN="your-token"

CLI Usage

Trace with Decision Export

# Trace transpiled binary with decision capture
renacer --trace-transpiler-decisions \
        --otlp-endpoint http://localhost:4317 \
        -- ./transpiled_app

Combined with Source Mapping

# Full transpiler debugging pipeline
renacer --transpiler-map app.map.json \
        --trace-transpiler-decisions \
        --otlp-endpoint http://localhost:4317 \
        --show-transpiler-context \
        -- ./app

Decision Trace Format

Each decision trace contains:

{
  "timestamp_us": 1700000000000,
  "category": "TypeMapping",
  "name": "infer_return_type",
  "input": {
    "python_type": "list[int]",
    "context": "function_return"
  },
  "result": {
    "rust_type": "Vec<i32>",
    "confidence": 0.95
  },
  "source_location": "app.py:42",
  "decision_id": 12345
}

Integration with entrenar CITL

Decision traces flow to entrenar's pattern store:

┌─────────────┐    ┌─────────────┐    ┌─────────────┐
│   renacer   │───▶│    OTLP     │───▶│  entrenar   │
│  (tracing)  │    │  (export)   │    │   (CITL)    │
└─────────────┘    └─────────────┘    └─────────────┘
                                            │
                                            ▼
                                   decision_patterns.apr

When rustc errors occur, entrenar queries accumulated patterns to suggest fixes—without LLM calls.

Batch Export

Renacer batches decision traces for efficient export:

• batch_size: Decisions per batch (default: 100)
• flush_interval_ms: Max wait before flush (default: 1000ms)
• queue_size: Offline resilience buffer (default: 10000)

Queue Overflow Handling

If the queue fills (network outage), oldest decisions are dropped:

// Stats available via API
exporter.stats().decisions_dropped  // Count of dropped decisions
exporter.stats().decisions_exported // Successfully exported

Retry Logic

Exponential backoff with jitter:

Metrics

Export metrics for observability:

let stats = exporter.stats();
println!("Queued: {}", stats.decisions_queued);
println!("Exported: {}", stats.decisions_exported);
println!("Dropped: {}", stats.decisions_dropped);
println!("Batches sent: {}", stats.batches_sent);
println!("Batches failed: {}", stats.batches_failed);

See Also

• CITL Integration - Full CITL workflow
• Transpiler Integration - Source mapping
• Distributed Tracing - OpenTelemetry spans