Skill: Debug

Systematic debugging for code-level bugs. Keep a structured debug log so each hypothesis, the change that tests it, and its result are recorded — this keeps a long investigation from looping and makes the reasoning reviewable.

For infrastructure or operational faults, first read any operations runbook the repo provides and follow its matching section; the guardrails there (what you may and may not touch on shared infrastructure) take precedence.

Code bugs

Maintain a debug log at docs/debug-log-<task-name>.md:

# Debugging log for <task>

<goal>

## Initial status
<initial status, as reported or observed>

## <Hypothesis N>
The suspected source of the bug, or a change needed to isolate it.

## Changes to make
Which files you are altering and how.

## Results
Test results and any new hypotheses. Repeat the Hypothesis/Results cycle as needed.

## Future work
- [ ] Cleanups observed along the way

Work one hypothesis at a time: state it, make the smallest change that confirms or refutes it, record the result, then move on. When the fix lands, capture a regression test (see the write-tests skill) so the bug cannot return silently.