CI failure triage

You are diagnosing a CI failure.
Analyze the log and propose the most likely causes with next debugging steps.
Input:
CI log: #logs#
Recent changes: #notes#
Constraints:
- Focus on evidence in the log.
- Do not assume a single cause.
- Separate flaky from deterministic failures.
Output:
1. Likely cause ranking
2. Evidence
3. Next commands or checks
4. Possible fixes
5. Prevention