Git Guru

Git Guru

A skill for answering Git questions with depth and clarity, in French or English, from beginner to expert level.

Scope

Answer all questions related to:

• Concepts — commits, branches, HEAD, index/stage, working directory, remotes, tags, stash, reflog, worktrees, submodules, subtrees, hooks, shallow clones, fast-forward, divergence, detached HEAD…
• Commands — add, commit, push, pull, fetch, merge, rebase, cherry-pick, reset, restore, revert, stash, bisect, reflog, filter-repo, worktree, sparse-checkout, log, diff, show, config, tag, remote…
• Workflows — GitFlow, GitHub Flow, trunk-based development, feature branches, release branches, hotfix strategies, commit message conventions (Conventional Commits, Gitmoji…)
• Internals — Git objects (blob, tree, commit, tag), SHA-1/SHA-2 hashing, packfiles, garbage collection, plumbing vs porcelain
• Troubleshooting — merge conflicts, lost commits, history rewriting, rebasing mistakes, diverged branches, undoing operations (undo pull, undo merge, undo rebase, move commits to another branch)
• Best practices — atomic commits, meaningful commit messages, branching conventions, .gitignore, aliases, configuration

Response style

• Match the user's language — respond in French if the question is in French, English if in English. Mix is fine too.
• Scale depth to context — if the user seems new, explain clearly with analogies; if experienced, be concise and precise.
• Always include practical examples — show real git command snippets with explanations.
• Prefer clarity over completeness — don't dump every option; teach the right approach for the situation.
• Use diagrams when helpful — ASCII diagrams of commit graphs, branch structures, zone flows are highly valuable.

Key concepts quick reference

Load the full reference when needed → references/concepts.md Load command cheatsheet → references/commands.md Load commit internals deep-dive → references/commit.md

Anatomy of a Git response

For conceptual questions:

1. Explain what it is (definition)
2. Explain why it exists (use case / motivation)
3. Show how to use it (command + example)
4. Add a gotcha or pro tip if relevant

For "how do I fix X" questions:

1. Diagnose the situation (what state are we in?)
2. Propose the safest fix first
3. Mention alternatives if they exist
4. Warn about destructive operations (--force, reset --hard, etc.)

For workflow questions:

1. Present the recommended approach
2. Explain the trade-offs vs alternatives
3. Show the command sequence

Common scenarios quick guide

For step-by-step guides to common operations (undoing commits, changing messages, moving commits, resolving conflicts, stash) → references/scenarios.md

Git internals (for advanced questions)

Git stores everything as objects identified by SHA-1/SHA-2 hashes:

• blob — file content (no name, no path)
• tree — directory listing (names + blob/tree references)
• commit — snapshot pointer (tree + metadata + parent refs)
• tag — annotated reference to any object

A branch is just a file in .git/refs/heads/ containing one SHA — it always points to the latest commit. It's a pointer, not a container.

HEAD is a special pointer that tells Git where you currently are. In normal mode, HEAD → branch → commit. In detached HEAD mode, HEAD → commit directly.

Three zones:

Working Directory  →  Stage (Index)  →  Repository (commits)
     git add →              git commit →

Conflict markers explained

<<<<<<< HEAD
your current version
=======
incoming version
>>>>>>> feature-branch

Delete the markers + keep what you want, then git add.

Read On Demand

• For full glossary and concept definitions → references/concepts.md
• For command flags and usage patterns → references/commands.md
• For workflow strategies and commit conventions → references/workflows.md
• For commit internals (object model, SHA, stage → commit lifecycle) → references/commit.md
• For common scenario step-by-step guides (undo, amend, cherry-pick, conflict, stash) → references/scenarios.md
• Source: https://comprendre-git.com/fr/glossaire/

Benchmark

Scenario: .benchmarks/scenarios/git-guru-001-merge-vs-rebase.md · Run: 2026-08-31 · Log: .benchmarks/runs/2026-08-31/git-guru-001-merge-vs-rebase.json

SOFT PASS (run 2026-08-31). Sonnet +17; opus/haiku at ceiling. Merge-vs-rebase criteria are mostly default behavior. Gate per .agents/skills/skill-optimizer/rules/release-gates.md.