explain-errorlisted

# Explain Error ## When to use Use this skill whenever a test, build, or runtime failure needs diagnosis before you change anything. ## Steps 1. Read the full error and the referenced file:line; don't stop at the last line. 2. Reproduce minimally if the cause is unclear. 3. Identify the root cause: type mismatch, None, version drift, config, race. 4. Propose the smallest correct fix and explain why it resolves the cause. 5. Suggest a guard (test, assertion, type) so it does not recur silently. ## Examples - "Why is this TypeError thrown here?" - "Explain this CI failure and how to fix it" ## References Distinguish the symptom from the cause; fix the cause, and add a regression test so the same error is caught next time.