Call Tracing

Build call trees showing how functions are reached from entry points.

Iron Laws - Never Violate These

1. Always use mix xref callers first - It's authoritative; grep is fallback only
2. Stop at entry points - Controllers, LiveView callbacks, Oban workers, GenServer callbacks
3. Track visited MFAs - Prevent infinite loops from circular calls
4. Extract argument patterns - Just knowing "who calls" isn't enough; HOW they call matters
5. Max depth 10 - Deeper trees indicate architectural issues, not useful traces

When to Build Call Tree (Use Proactively)