Repo Troubleshooting Guide

Repo Troubleshooting Guide

Turn a repository into a structured, professional troubleshooting guide. The guide is grounded in two sources: (1) the detected stack (languages, frameworks, services, infra) and (2) mined evidence from the actual code (raised exceptions, human-readable error strings, env vars, ports, Docker services, CI, and TODO/FIXME markers). Generic advice is a fallback; repo-specific evidence always wins.

What you produce

A single Markdown file (default TROUBLESHOOTING.md at the repo root) with: a quick setup checklist, issue sections organized by subsystem, recovery procedures, a known-gaps section from TODO markers, and a "still stuck" section. Clean professional tone — no emoji, no motivational filler. See references/output-template.md for the exact structure.

Workflow

Follow these phases in order. Each phase has a clear endpoint so you can checkpoint.

Phase 1 — Locate the repo

Determine the repository path. If the user uploaded or cloned a repo, use that path. If they named a public repo, clone it (shallow): git clone --depth 1 <url> /tmp/<name>. If the path is ambiguous, ask which directory is the repo root before proceeding.

Phase 2 — Scan for evidence

Run the scanner to produce a structured inventory. It is stdlib-only Python and writes JSON describing the stack and failure-mode signals:

python scripts/scan_repo.py <repo-path> --out /tmp/evidence.json

Read /tmp/evidence.json. Key fields:

• languages, frameworks, services, docker, ports, ci — the detected stack
• env_vars — environment variables the code reads
• evidence.raised_exceptions, evidence.thrown_errors, evidence.exception_classes — error types defined/raised in the code
• evidence.error_messages — literal human-readable error strings found in the code
• evidence.todo_markers — TODO/FIXME/HACK/XXX/BUG comments with file locations
• existing_docs, run_commands — README/docs present and how the project is run

If scan_truncated is true, the repo is large; the scan is still representative but note that the evidence list is partial.

Phase 3 — Map evidence to issues

Read references/issue-catalog.md. For each detected stack element, pull the relevant catalog entries only if that technology is actually present in the scan, and adapt their error text, ports, and commands to what the scan found. Then, for each notable mined signal (a raised exception, a literal error string, a cluster of related TODOs), draft a repo-specific issue: name it after the real error, state the likely trigger, and give the most plausible numbered fix. Do not fabricate error strings you didn't find — if you only have a symptom, describe the symptom.

Prefer depth on what the repo actually does over breadth of generic advice. A repo with no frontend gets no frontend section.

Phase 4 — Write the guide

Read references/output-template.md and write the guide to that structure. Hard rules:

• No emoji; professional ops-doc tone.
• Put literal error text (from the scan) in code blocks; otherwise describe the symptom.
• Fix steps are numbered, runnable, and use the repo's real commands, paths, ports, and service names. End multi-step fixes with a verification step.
• Order sections by subsystem, most-likely-to-break first (setup → deps → services → app).
• Length scales to the repo; don't pad.
• Include a "Known Gaps & TODOs" section built from evidence.todo_markers.

Phase 5 — Save and report

Write the file to TROUBLESHOOTING.md at the repo root (or docs/TROUBLESHOOTING.md if a docs/ directory exists). If a troubleshooting file already exists, say so and confirm before overwriting. Then give the user a 2–3 line summary: which subsystems are covered, how many issues, and anything the scan flagged (e.g. truncation, no env example, unresolved TODOs). If present_files is available, present the file.

Reference files

• scripts/scan_repo.py — the repo scanner (Phase 2). Run it; don't reimplement it.
• references/issue-catalog.md — common failure modes per technology (Phase 3).
• references/output-template.md — the exact output structure and authoring rules (Phase 4).

Notes

• The scanner is read-only and dependency-free; safe to run on any repo.
• Treat the scan as evidence, not gospel: if you can see the code, verify a detail before documenting it. The goal is a guide a teammate could follow without you in the room.

Next steps: After delivery, suggest drift-check to confirm the new TROUBLESHOOTING.md doesn't contradict the existing README, CONTEXT.md, or CONTRIBUTING — the most common drift pattern after generating an ops doc is a stale port number, a renamed service, or a setup step that disagrees with the canonical install instructions. Skip the suggestion if the repo has no other docs to cross-check.