Thalarch Debug

Causal Debug Protocol

Phase 1 — Reproduce and bound

Record:

• exact expected vs actual behavior;
• reproduction or failure evidence;
• frequency if intermittent;
• environment/version;
• earliest known good state when available.

Phase 2 — Trace the causal chain

Trace backward from the symptom.

At each boundary ask:

• what entered?
• what exited?
• what state/config was assumed?
• where is the first violated contract?

Instrument boundaries rather than guessing downstream fixes.

Phase 3 — Compare a working analogue

Find the closest known-working path and compare all meaningful differences.

Do not dismiss small differences without evidence.

Phase 4 — Hypothesis

Write exactly one primary hypothesis:

Cause: ... Because: ... Prediction if true: ... Observation that disproves it: ...

Then run the smallest experiment that separates this hypothesis from alternatives.

Phase 5 — Fix source, prove regression

Prefer the earliest incorrect state or broken contract.

Where practical, demonstrate:

• fail before;
• pass after;
• nearby regression checks remain green.

Breaker

After three failed hypotheses:

• stop patch accumulation;
• re-open assumptions;
• examine shared state, ownership, lifecycle, and architecture;
• use a fresh agent/context for the reassessment.