debug-triage

name	debug-triage
description	Use when triaging a pasted error, stack trace, or terminal transcript. Activates on "debug this", "fix this", "why is this broken", or when a user pastes red terminal output. Produces a tight cause-fix-test report, not a lecture.
allowed-tools	Read Grep Glob Bash(git log:*) Bash(git blame:*) Bash(git diff:*)

debug-triage

When to activate

• User pastes a terminal or PowerShell transcript containing an error.
• User pastes a stack trace.
• User says "debug", "fix this", "why is this broken", "what's going on here".

Do NOT activate for refactoring requests, feature work, or general code review -- those are separate tasks.

Steps

1. Parse the actual error. Read stack traces bottom-up. The top frame is usually the symptom; the root cause is deeper in the stack or earlier in the log. Ignore generic first lines like "Traceback (most recent call last):" or "Uncaught Error".
2. State the likely cause in one sentence. Not a paragraph. "Null dereference on user.profile because the auth middleware returns null for unverified emails."
3. Propose the fix as a diff or command. Not prose. Either a code snippet showing before/after, or the exact shell command to run.
4. Name a regression test. Where it would live (tests/auth/email_verify_test.py), and what assertion would catch this bug next time. One line.
5. Flag sibling updates. If the fix changes behavior documented in README, CHANGELOG, or any doc file, list them. If not, say "none".

Rules

• Don't ask the user to reformat the paste. Parse whatever they gave you.
• Fix first, explain if asked. Don't narrate what the error means at length.
• Ambiguous errors: if 2+ causes are equally likely, pick the likeliest and say so in one line. Do not dump all possibilities unless asked.
• Recent changes are suspect. Run git log -5 --oneline -- <file> on the failing file. If a recent commit touched the failing line, mention it.
• Environment first. If the error looks like it could be environmental (missing env var, wrong Node/Python version, CRLF line endings, path with spaces), check the environment before hypothesizing code bugs.

Output

Cause: <one line>
Fix: <diff or command>
Regression test: <path + what it asserts>
Siblings to update: <list or "none">

No preamble. Lead with Cause:.