debug-reproduce-isolate-fix

name	Debug (reproduce -> isolate -> fix)
description	Systematically diagnose and fix a bug instead of guessing.
triggers	["debug","fix bug","why does this fail","investigate error"]

Debug (reproduce -> isolate -> fix)

Use this to track down a bug methodically.

Steps

1. Reproduce. Get a reliable, minimal repro. If you can't reproduce it, gather the exact error, stack trace, inputs, and environment first.
2. Isolate. Narrow the failure: read the stack trace, add targeted logging, bisect the input or the recent changes. Form a hypothesis about the root cause.
3. Confirm root cause. Verify the hypothesis — don't fix symptoms. State why it fails.
4. Fix. Apply the smallest change that addresses the root cause. Avoid unrelated edits.
5. Verify + guard. Re-run the repro to confirm the fix, run the broader tests for regressions, and add a test that would have caught this bug.

Notes

• Resist guess-and-check. One confirmed root cause beats five speculative edits.
• Remove temporary logging/instrumentation before finishing.