Gated Dual Clone

Gated Dual-Clone Workflow

One-liner · 一句话

EN — Clone the upstream twice: a gateway repo that pushes, and a satellite repo that builds. The satellite's origin points at the local gateway path — so a stray git push from the compile tree is physically unable to reach the remote.

ZH — 把上游仓库 clone 两份:一个 gateway 仓库负责 push,一个 satellite 仓库只读编译。satellite 的 origin 指向本地 gateway 路径, 编译树里误跑一条 git push 在物理上也够不到远程。

Should I use this? · 该不该用

→ See references/decision-checklist.md

Four yes/no questions. Three or more "yes" → use this skill. Otherwise fall back to a single repo or git worktree.

四道是非题:≥ 3 个 yes 用本 skill,否则单仓库或 git worktree 更合适。

Minimal bootstrap · 最小搭建

scripts/bootstrap.sh \
  --remote          git@gitlab.example.com:team/project.git \
  --upstream-branch release \
  --push-branch     feature/alice-auth \
  --gateway-dir     ~/projects/foo-work \
  --satellite-dir   ~/projects/foo-verify \
  --user-email      alice@example.com \
  --user-name       alice

All 7 flags are required. --dry-run prints the command sequence without executing. --force is only valid for empty target dirs (non-empty is always rejected; clean up by hand first). See scripts/bootstrap.sh --help for detail.

Post-setup · 搭建完成后(3 道检查)

bootstrap.sh verifies three safety layers before exiting 0:

• Gate A · Protocol wall — cd satellite && git push rejected ("DISABLED" in error). Satellite's origin is a local path; no network route to upstream exists.
• Gate B · Explicit disable — Satellite's push URL is literally set to DISABLED, so even malformed config still errors fast instead of silently trying.
• Gate C · Pre-push hook — Gateway's pre-push hook rejects any push to a protected-branch regex (default: the upstream branch passed in).

Gate failures halt bootstrap with a clear reason — nothing is left in a partial state that the user has to hand-clean.

三道检查都过才算 bootstrap 成功。任一失败会明确说明原因,不留一半成品。

Daily operations · 日常操作

→ See references/daily-workflow.md

The core loop: edit in gateway, sync satellite with scripts/sync-satellite.sh, build in satellite, push from gateway, open MR/PR. Four commands, copy-paste ready.

日常 4 步:在 gateway 里改 → sync-satellite.sh 同步到 satellite → satellite 里编译 → gateway 里 git push → GitLab / GitHub 上发 MR/PR。 cheatsheet 里每步都是现成命令。

Safety model · 安全模型

Three layers, each independent. Any one holds; all three together is belt, braces, and shoulder strap.

1. Protocol layer — satellite's origin is a file path; no TCP/SSH route to upstream exists from the compile tree.
2. Config layer — satellite's push URL = literal DISABLED. Explicit failure mode.
3. Hook layer — gateway's pre-push hook rejects protected-branch refs.

Critical caveat · 关键注意: Client-side git hooks are advisory, not enforcement. --no-verify bypasses them. Real protection = server-side protected-branch rules in GitLab / GitHub / Gerrit. This skill's hook is a second layer — catches finger-slips, not determined bypass. Enable server-side branch protection alongside.

客户端 hook 只是提醒,不是强制边界。--no-verify 可以绕过。真正的保护 在托管平台的 protected-branch 规则上。本 skill 的 hook 是第二层,接手滑, 不防恶意。服务端保护一起开。

Variants · 变体

• 1 gateway + N satellites — run bootstrap.sh again with --skip-gateway + a new --satellite-dir. Useful for verify / debug / test trees.
• 3-clone with reproducibility gate (see below) — add a clean-verify clone on separate disk/machine, with a pre-push hook that refuses to push anything clean-verify hasn't stamped. Trade extra disk + extra build time for catching "works on SSD, fails on HDD / CI" bugs before they reach upstream.
• Worktree fallback — if disk is tight (< 2× source size) and single developer, single machine: git worktree trades isolation for disk. See decision-checklist.md for when worktree beats this skill.
• Hosting differences — GitLab MR, GitHub PR, Gerrit push-to-refs/for/*. The skill is host-neutral; protected-branch regex is a per-project flag.

Optional 3rd clone · reproducibility gate · 可选 第 3 仓 · reproducibility 关卡

For projects where a failed build on CI (different filesystem, different disk speed, different filesystem cache state) has a real cost — add a clean-verify clone on a separate disk (or separate machine) and gate every push on a from-scratch full-build in it.

When to use (all four should be true):

1. Daily dev happens on SSD; CI / shipping happens on HDD or remote machine.
2. The project has reproducibility bugs that only surface from a cold, clean tree (SSD cache / generated files / stale build artefacts hide them on the iteration clone).
3. The push path is high-stakes (production branch, signed release, audit trail required).
4. The team already has discipline to run a pre-push command.

Topology:

                 ┌──────────┐       ┌──────────┐       ┌───────────────────┐
   upstream ───► │ gateway  │ ────► │satellite │       │  clean-verify     │
   (push only    │ (dev +   │ sync  │ (build · │       │  (pre-push gate · │
   from gateway) │  push)   │ via   │  disabled│       │   HDD / diff disk)│
                 │   SSD    │ local │  push)   │       │                   │
                 └──▲───────┘ path  └──────────┘       └───▲───────────────┘
                    │                                       │
                    │ pre-push hook reads .git/last-clean-verify
                    │ and refuses to push a commit whose sha ≠ stamped
                    │                                       │
                    └─── clean-verify-run.sh stamps on success ─┘

Bootstrap it:

scripts/bootstrap.sh \
  --remote              git@gitlab.example.com:team/project.git \
  --upstream-branch     release \
  --push-branch         feature/alice-auth \
  --gateway-dir         ~/projects/foo-work \
  --satellite-dir       ~/projects/foo-verify \
  --clean-verify-dir    /mnt/hdd/foo-clean-verify \
  --user-email          alice@example.com \
  --user-name           alice

Same as the 2-clone bootstrap, plus --clean-verify-dir=<path>. The script adds:

• Step 5b — git clone the clean-verify from gateway (same local-path trick as satellite · origin on a local path, never the real remote).
• Step 6b — set pushurl = DISABLED on both origin and the diagnostic upstream remote. Check out <push-branch>.
• Gate D — in Step 7 post-setup, verify clean-verify push is DISABLED.
• Pre-push hook gets a 2nd gate — install-hooks.sh is invoked with --enforce-clean-verify, which adds a "stamp match" check alongside the protected-branch check.

Daily flow (5 steps instead of 4):

1. Edit in gateway, commit.
2. sync-satellite.sh → satellite → build + test there (fast iteration).
3. When ready to push, run:

   scripts/clean-verify-run.sh \
     --gateway-dir=<gw> --clean-verify-dir=<cv> \
     --push-branch=<br> --build-cmd='<full-build command>' --yes
   

   This syncs clean-verify from gateway, runs git clean -fdx (drops every untracked/ignored file), runs your full build end-to-end, and on success writes gateway/.git/last-clean-verify.
4. git push origin <push-branch> — the hook reads the stamp, refuses if commit doesn't match. Emergency bypass: git push --push-option=allow-unverified (use sparingly; the point of the gate is that it holds).
5. Raise MR/PR.

What this catches that 2-clone doesn't:

• SSD-only bugs: code depends on files that happen to be in OS filesystem cache on the dev SSD but not on a cold HDD.
• Stale-artefact bugs: satellite has build products from an earlier commit that accidentally satisfy a missing #include / missing codegen that the current commit wouldn't produce fresh.
• Dirty-tree bugs: satellite has hand-edits the author forgot about; they pass the build; clean-verify starts from git HEAD and fails.
• Build-command drift: --build-cmd is sha256-hashed into the stamp; if team changes build command out from under you, next push asks for a re-verify.

Paired evaluator: gated-dual-clone-audit auto-detects 3-clone mode when you pass --clean-verify-dir, and runs 4 extra gates (S9-S11 + C9 + B4) to re-verify the topology on demand.

Files · 文件

• scripts/bootstrap.sh — the main setup command, runs all 8 steps + 3 gates (4 gates in 3-clone mode) · accepts optional --clean-verify-dir
• scripts/sync-satellite.sh — fetch / reset-hard / merge-ff modes for syncing satellite from gateway
• scripts/clean-verify-run.sh — sync + clean + full-build + stamp · the pre-push reproducibility gate for 3-clone mode
• scripts/install-hooks.sh — writes the pre-push hook on the gateway · --enforce-clean-verify adds the stamp-match gate
• scripts/check_before_mr.sh — 5 checks to run right before opening the MR (clean tree · clean-verify repo exists · stamp present · stamp sha == branch head · remote == local). For push-early / MR-late projects — see below
• references/decision-checklist.md — when to use / when not to use
• references/daily-workflow.md — 4-step cheatsheet
• references/patterns.md — N-satellite / worktree fallback / GitHub-GitLab-Gerrit shapes
• references/guardrails.md — why the three gates work / when they break / how to verify
• references/server-side-enforcement.md — GitLab / GitHub / Gerrit / pre-receive / Actions templates (real enforcement beyond advisory client-side hook)
• references/troubleshooting.md — 10 common failures, symptom → diagnose → fix → prevent
• references/comparison.md — dual-clone vs worktree vs single-repo, 11-dimension table

Push-early / MR-late · 先推分支,最后才开 MR

有些项目这样走:个人分支随时 push 到远端当备份,一整个主题做完才开 MR。 这时 install-hooks.sh --enforce-clean-verify 那道会碍事 —— 它不看分支名, 任何 push 都拦,于是每次备份性质的 push 都要 --push-option=allow-unverified。

绕过一旦变成肌肉记忆,哪天真该拦的那次也会顺手绕过 —— 比关掉更糟, 因为还以为有人看着。

而真正该卡的是开 MR 那一刻,那是托管平台上的动作,不是 git 事件,pre-push hook 根本接不到。所以这类项目应该:

# 1. 建仓时【不加】 --enforce-clean-verify(或事后把 hook 里 enforce_cv 改 0)
#    Gate 1(保护分支)照旧生效,个人分支随便推

# 2. 开 MR 之前跑这个,五项全过才去点开 MR
scripts/check_before_mr.sh \
  --gateway-dir=<gateway> \
  --clean-verify-dir=<clean-verify> \
  --branch=<待 MR 的分支>

五项:

怎么选:每次 push 都该验 → 用 --enforce-clean-verify; 先推后 MR → 关掉它,改用 check_before_mr.sh。两个都不用 = 那道关卡不存在。

Reference · 参考

• Anthropic · harness design for long-running apps
• Full design spec: docs/design-mr-gated-dual-repo.md
• Live demo: demos/gated-dual-clone/index.html