Worktree Isolation

Provision one owned runtime envelope for a concurrent worktree or non-bootstrap test run. Production-like QA should prefer eng-qa-bootstrap, which adds a manifest, provider homes, browser policy, and targeted teardown evidence.

Creating the parallel checkout itself is a separate step: make worktree-new SLUG=<slug> (→ ./scripts/worktree.sh) adds a sibling worktree and bootstraps it (mise pins, bun install + skill/AGENTS.md symlinks; BUILD=1/E2E=1 opt-ins); make worktree-bootstrap preps an existing checkout; ./scripts/worktree.sh rm <slug> removes. Go caches are shared machine-wide — no per-worktree Go setup. This skill then isolates the RUNTIME state that agents inside that worktree use. Opt-in make gate-full and local E2E self-queue machine-wide (L-030); required scoped lanes need no lock and PR CI owns full verification.

Required Inputs

• scenario-slug (optional): a short kebab-case slug used to name the COMPOZY_HOME directory and tmux socket. Defaults to compozy-iso-<timestamp>.

Procedures

Step 1: Confirm the Concurrency Branch

1. Look for explicit signals in the user's request: parallel-worktree language, "another agent is running", "tem outro agent trabalhando", "QA in parallel", or invocation under a worktree path like Compozy/_worktrees/<slug>/.
2. If no concurrency signal is present and no parallel runtime is planned, stop; this skill does not apply.
3. Confirm the scenario-slug, defaulting to a timestamped slug when omitted.

Done when: the concurrent runtime/test branch and one unique scenario slug are explicit.

Step 2: Allocate COMPOZY_HOME

1. Run the bootstrap/mutating helper python3 .agents/skills/eng/eng-worktree-isolation/scripts/allocate-isolation.py --slug "<scenario-slug>" [--prefer-worktree]. Pass --prefer-worktree only from an actual parallel worktree. The script:
   • Creates a unique COMPOZY_HOME directory under ${TMPDIR:-/tmp}/compozy-iso-<slug>-<random>/ OR uses the worktree-scoped Compozy/_worktrees/<slug>/.compozy/ when invoked from a worktree.
   • Picks a free TCP port on 127.0.0.1 for the daemon HTTP server.
   • Creates a unique UDS path under COMPOZY_HOME.
   • Picks a unique tmux socket path under the COMPOZY_HOME (e.g., ${COMPOZY_HOME}/tmux-bridge.sock).
2. The script prints export statements, including COMPOZY_ISOLATION_ROOT, suitable for eval "$(...)".

Done when: the allocator returns one non-default, owned root and unique HTTP/UDS/tmux addresses.

Step 3: Source the Envelope

1. Capture the exported variables: COMPOZY_ISOLATION_ROOT, COMPOZY_HOME, COMPOZY_HTTP_PORT, COMPOZY_UDS_PATH, TMUX_BRIDGE_SOCKET.
2. For shells: eval "$(python3 .agents/skills/eng/eng-worktree-isolation/scripts/allocate-isolation.py --slug "<slug>" [--prefer-worktree])".
3. For Make/CI invocations: pass the variables as overrides to the daemon start command.
4. Confirm the daemon does NOT write to ~/.compozy/ or default port 23230.

Done when: the current shell exposes the exact allocator output and no default runtime path is reachable by the planned command.

Step 4: Verify Isolation Before Action

1. Confirm COMPOZY_HOME is non-default and writable.
2. Confirm the chosen ports are not already bound (re-pick if necessary).
3. Confirm the tmux socket path is non-default and not held by another process.
4. Print a one-line summary: slug, COMPOZY_HOME, http port, uds path, tmux socket.

Done when: every address is free immediately before launch and the summary identifies the owned root.

Step 5: Run the Isolated Scenario

1. Hand off to the inner skill (eng-real-scenario-qa, qa-execution, make test-e2e-runtime, etc.).
2. Prefer eng-qa-bootstrap for production-like local QA because its own allocator also provides provider homes, a manifest, browser policy, Web proxy env, and teardown evidence.
3. Inner skills inherit the env via the shell session. Do not re-allocate.

Done when: every child process uses the same envelope and none writes to another worktree or default home.

Step 6: Cleanup (processes ALWAYS, files optionally)

1. Process teardown is mandatory on every terminal path. Run the mutating teardown helper only for this run's envelope: python3 .agents/skills/eng/eng-qa-bootstrap/scripts/teardown-qa-env.py --root "$COMPOZY_ISOLATION_ROOT"
2. Confirm the targeted teardown reports TEARDOWN_ALL_CLEAN=true. Survivors are a blocking failure.
3. The COMPOZY_HOME directory is left in place for forensic inspection unless the caller explicitly requests --purge for a temporary envelope.
4. Never purge a worktree-scoped .compozy; it belongs to the user's checkout.
5. Use make qa-reap or teardown --all only for an intentional machine-wide stale-lab recovery, never as normal cleanup while other runs may be active.

Done when: the owned envelope is clean, unrelated labs remain untouched, and any retained files contain no live process state.

Error Handling

• No free port available: retry with a wider range. If still no luck, surface the busy ports and exit.
• COMPOZY_HOME path collision: the script uses random suffixes; collision is essentially impossible. If it happens, retry once.
• User invokes without concurrency signal but with --force: apply isolation. Some users always want isolated runs.
• Worktree-scoped path lacks write permission: fall back to TMPDIR-scoped path with a logged warning.
• Targeted teardown cannot prove ownership: stop and report the root/PIDs; never widen normal cleanup to --all.