Hakorune compiler is built by Hakorune itself (Stage‑N by Stage‑(N‑1)).
Freeze v1 of language spec, MIR(JSON v0) schema, minimal stdlib/ABI.
Rust remains a thin kernel (ABI/OS/HostHandle); no language semantics. 削減％は指標にしない。
開発作業の主戦場は lang/ 配下（Nyash 側）。Rust は hako ABI で接続し、必要最小限の修正（不具合/境界整備）に限定。

Scope

Selfhost line only (Fronts+Compiler+CoreVM). Rust line stays unchanged by default (gated).
No feature expansion; only correctness, diagnostics stabilization, and fail‑fast.
Runner は Core 直行（JSON→Interpreter）を既定にし、Ny ラッパー（NyVmDispatcher.run）は TTL の互換経路に留める。

Acceptance Criteria

Selfhost build
- Stage 0 (Rust) builds Stage 1 (Hakorune compiler AOT/EXE)
- Stage 1 builds Stage 2 (same sources) with identical outputs (hash or canonical diff)
- Optionally Stage 2 builds Stage 3 for extra confidence (time‑boxed)
Spec/ABI freeze
- MIR(JSON v0) fields and meaning are fixed and documented
- Core diagnostics use stable tags; smokes cover success/negative
Exit semantics
- Numeric return maps to process exit code under Core route
- Non‑numeric return prints stable line; rc=0 only in Direct path
Quick/integration profiles
- Gate off by default. With opt‑in gates, quick selfhost canaries are green; integration set is ≥95% pass.

Gates (default OFF)

Notes

Strictness is at boundaries. Unknown keys in JSON/payload fail fast with stable tags.
Rollback is gate removal; kernels stay intact.
Strategy reference: ../FROZEN_TOOLCHAIN_STRATEGY.md
ABI 境界（hako ABI）は最小仕様（呼出規約/型/例外/戻り/所有）を安定化。変更は gate/TTL 配下で段階導入。

Progress (to date)

Gate‑C(Core) numeric rc symmetry fixed（file/pipe、plugins on/off 代表OK）
HKI（kni.*）正/負 canary が quick curated で緑（console/time/fs）
Prelude STRICT（DeclOnly）を DFS/AST/unified の全経路に配線（決定的 Fail‑Fast）
S2(strict) 既定ON。Emitter は ValueId 再番号・順序固定・単一パスで決定化済み
Core mir_call: Array/Map の代表メソッド（size/push/pop/get/set/len）と負例タグが固定化
Selfhost runner: nyvm(Core) 直行へ強制。Ny ラッパー経路の Unknown module function: NyVmDispatcher.run/1 を回避。
MIR(JSON v0) Reader: unary（unop）/params/Constructor/Const のネスト表現に対応。自己ホスト最小ケースで未定義レジスタの使用を解消。
Selfhost 最小スモーク（emit→parse→execute）が PASS（quick, opt‑in）。

Phase 20.17 — Full Self‑Hosting (Freeze v1)