py2rs-env-bootstrap

name	py2rs-env-bootstrap
description	[DRAFT] 跑通迁移 seam 的最小环境。根据项目选择 FFI、CLI、service、Tauri command、library 或 pipeline adapter，并证明参数、返回值、错误、日志和并发边界可用。

py2rs-env-bootstrap — Seam Bootstrap

本阶段只证明“旧/新实现能通过选定 seam 被稳定调用”。不要开始业务迁移。

Pick The Seam

从 py2rs-dep-align 的记录读取 seam 类型、applied rewrite profile、crate reconnaissance status、实际依赖和 preference deviations。偏好采集本身不能代替 这份单元级依赖记录。还要读取 execution policy、canonical shared dependency registry，以及并行模式下 coordinator 分配的 Cargo build slot。Confirm the unit's behavior_verification names an independently comparable legacy public seam.

• ffi: Python 调 Rust extension。
• cli: legacy caller 调 Rust binary 或反向包装。
• service: HTTP/gRPC/API boundary。
• tauri-command: desktop command facade。
• library: Rust crate API 被旧入口调用。
• pipeline: data stage adapter with fixtures.

不要为不需要的 seam 建 demo。

Demo Matrix

每种 seam 都必须证明：

• 参数传递：字符串、数字、列表/对象或项目核心 payload。
• 返回值：结构化结果能被旧调用方理解。
• 错误：新实现错误能映射为旧接口可处理的错误。
• 日志/trace：调用链能定位到 unit、operation 和 source error。
• 并发/重复调用：不会死锁、污染状态或破坏缓存。
• rollback：切回旧 owner 后同一调用仍可运行。

Example Deliverables

Use project conventions. If none exist:

bootstrap/
  README.md
  run_all.sh
  cases/
    hello_roundtrip.*
    error_mapping.*
    concurrent_calls.*

For Python FFI projects, the old maturin + pyo3 demo is still valid. For Tauri or service projects, use command/API fixtures instead.

Acceptance Output

Record results in the manifest or a Stage 0 file:

env_bootstrap:
  status: done
  seam: tauri-command
  dependency_record: "rewrite-records/example-dependencies.yaml"
  applied_profile: standard
  crate_reconnaissance: complete
  behavior_verification:
    legacy_public_seam: "tauri command input/output/error boundary"
    required_observations:
      - command roundtrip
      - error projection
    comparison_policy:
      default: exact
      tolerances: []
    evidence: []
  canonical_dependencies:
    - "manifest/shared-dependencies.yaml#burn-missing-capability"
  cargo_build_evidence: "coordinator build record or serial command output"
  cases:
    roundtrip: PASS
    error_mapping: PASS
    trace_context: PASS
    repeated_calls: PASS
    rollback: PASS
  notes:
    - "New backend can be called behind existing command facade."

Failure Handling

• Missing dependency: return to py2rs-dep-align.
• Crate reconnaissance is blocked, or required evidence is missing: do not bootstrap the Rust path. Return to reconnaissance/dependency alignment.
• Cargo manifest/lockfile does not match the applied dependency record: return to py2rs-dep-align; do not silently add a different framework here.
• A dependency resolves through /tmp or an agent-private copy: reject it and return to dependency alignment so the implementation is promoted into the canonical project root.
• In coordinated parallel mode, a worker has no coordinator build slot: do not start a competing Cargo build or create an isolated target directory silently.
• A hard framework preference conflicts with the seam: return to the user for a preference decision, then update NOTES.md and the dependency record.
• The legacy public seam is missing or cannot support independent old/new comparison: return to dependency alignment to move the seam, re-cut the unit, defer it, or keep its legacy owner. A compile check is not behavior evidence.
• Bad error mapping: fix the bridge/adapter before business migration.
• Deadlock/blocking behavior: define async boundary before business migration.
• Rollback cannot be shown: the seam is not ready.

Exit Criteria

• The seam works without business rewrite code.
• Cargo manifests and lockfiles contain the dependencies selected for this seam, with no dependency added solely because it appeared in initialization notes.
• Shared dependencies resolve through registry-recorded project paths, not temporary or agent-private copies.
• Cargo build evidence follows the serial policy or the coordinator's build queue.
• The seam proves the declared behavior observations against the legacy path.
• Reconnaissance is complete, policy_rejected, manual, or explicitly user_disabled; the last case remains visible as residual risk.
• The demo uses the project's actual public interface shape where possible.
• The next migration unit can implement behind the seam without choosing new architecture.