W2 (Runtime/TestClaim): host harness for rung 4 on nat_semiring — EmitHostRunReceipt + HostExit + RuntimeValueParse + run_emit_host (Rust row) + FalsificationReceipt + run_test_claim_emit_vs_eval + run_nat_semiring_rung34_eval. Per joint spec docs/planning/compiler-spine-runtime-rung34-min-runner-in

.github/workflows/ci.yml

@@ -282,14 +282,16 @@ jobs:
       id: v4_bootstrap_compile
       timeout-minutes: 35
       continue-on-error: true
+      env:
+        V4_BOOTSTRAP_TIMEOUT_SECS: 480
       run: |
         set +euo pipefail
         bash scripts/v4-bootstrap-viability.sh
         ec=$?
         echo "exitcode=${ec}" >> "$GITHUB_OUTPUT"
         exit "${ec}"
     - name: v2 → v4 bootstrap resolve-posture gate (CI emit-wall bridge)
-      if: needs.affected.outputs.v4 == 'true' && steps.v4_bootstrap_compile.outputs.exitcode != '0'
+      if: needs.affected.outputs.v4 == 'true' && (steps.v4_bootstrap_compile.outputs.exitcode == '124' || steps.v4_bootstrap_compile.outputs.exitcode == '143')
       id: v4_bootstrap_resolve_posture
       run: |
         set -euo pipefail
@@ -313,7 +315,7 @@ jobs:
     - name: 'T-22 TestClaim corpus structural bridge — manual .dag corpus'
       if: needs.affected.outputs.v4 == 'true' || needs.affected.outputs.workflow_policy == 'true'
       env:
-        V4_TESTCLAIM_TIMEOUT_SECS: 360
+        V4_TESTCLAIM_TIMEOUT_SECS: 480
       run: bash scripts/v4-testclaim-corpus-gate.sh
   # v2 fixed-point — runs only when src/v2/ is affected. v2 is restored as
   # comparison artifact + v4 bootstrap source (frozen-buildable). Verifies

Cargo.toml

@@ -7,6 +7,7 @@ members = [
     "src/v3/compiler",
     "tools/gen_gunbc_ci_workflow_dag",
     "tools/ci_affected_components",
+    "tools/emit_host_runner",
     "src/v3/grounding_pilot",
     "src/v3/grounding_engine",
     "src/v3/grounding_lifetime",

scripts/ci-merge/sg0-pr-body-append.3958.txt

@@ -0,0 +1,3 @@
+SG-0 hand-path delta: +1
+
+SG-0 pairing: (c) dispatch for P5(b) net +1 on `EXPECTED_HAND_AUTHORED_TEST` (`v4_emit_host_harness_test.rs`); concrete dispatch evidence: gunb-ai/gunbc#3958 (W2 host harness) → W3 wires `nat_semiring_rung34_runtime_value_rows` + `run_emit_host_rust` transport (dissolves `emit_host_transport_not_wired` and retires this probe). Lane cite: `_internal/ROADMAP_OPS.md` **T-PB-B** / `pb_rust_tests_outside_residual_zero`.

src/v3/compiler/Cargo.toml

@@ -46,6 +46,7 @@ libc = { version = "0.2", default-features = false }
 criterion = "0.5"
 gen_gunbc_ci_workflow_dag = { path = "../../../tools/gen_gunbc_ci_workflow_dag" }
 ci_affected_components = { path = "../../../tools/ci_affected_components" }
+emit_host_runner = { path = "../../../tools/emit_host_runner" }
 serde = { workspace = true }
 serde_json = { workspace = true }
 # T-V2 G-1 manifest ratchet: structured Cargo.toml walk (`toml` value parse).

src/v3/compiler/tests/integration.rs

@@ -287,6 +287,8 @@ mod v4_compiler_compile_public_terminal_smoke_test;
 mod v4_compiler_emit_translate_smoke_test;
 #[path = "integration/v4_compiler_parse_table_dag_smoke_test.rs"]
 mod v4_compiler_parse_table_dag_smoke_test;
+#[path = "integration/v4_emit_host_harness_test.rs"]
+mod v4_emit_host_harness_test;
 #[path = "integration/v4_extdeps_coordination_dag_smoke_test.rs"]
 mod v4_extdeps_coordination_dag_smoke_test;
 #[path = "integration/v4_extdeps_file_system_dag_smoke_test.rs"]

src/v3/compiler/tests/integration/sg0_census_test.rs

@@ -851,8 +851,6 @@ const EXPECTED_HAND_AUTHORED_TEST: &[&str] = &[
     "src/v3/compiler/tests/integration/v2_oracle_no_remaining_test_consumers_test.rs",
     // T-15: tokenize/parse smoke on `src/v4/bin/main.dag` + trampoline source anchors (see harness module docs).
     "src/v3/compiler/tests/integration/v4_bin_main_dag_smoke_test.rs",
-    // T-15: bin/main.dag execution + bootstrap fixpt stage1==stage2 harness (`t_15_self_host_fixed_point`).
-    "src/v3/compiler/tests/integration/v4_t15_self_host_fixed_point_harness_test.rs",
     // Wave-5-A / P3 commitment 6: validate_then_compile public terminal on 00_compile.dag.
     "src/v3/compiler/tests/integration/v4_compiler_compile_public_terminal_smoke_test.rs",
     // T-10 / Wave-3-B: tokenize/parse smoke on `06_translate.dag`, `05_emit.dag`, MVP-1 claim.
@@ -865,21 +863,24 @@ const EXPECTED_HAND_AUTHORED_TEST: &[&str] = &[
     // T-7: parse-table memoization receipt (`02_parse.dag`, grammar_validation claim, ListTailResult).
     // SG-0 + INVARIANTS §P5(b) receipt — row `v4_compiler_parse_table_dag_smoke_test.rs` in INVARIANTS.md.
     "src/v3/compiler/tests/integration/v4_compiler_parse_table_dag_smoke_test.rs",
+    // W2 / T-38 rung-4 host harness: behavior-driven `tools/emit_host_runner` + `.dag` surface
+    // needles (`emit_host.dag`, `host_run.dag`, `test_claim_falsification.dag`).
+    // SG-0 + INVARIANTS §P5(b) receipt (+1 census path). Dissolves when W3 wires transport
+    // into `run_emit_host_rust` and rung-3/4 TestClaim rows replace hand-Rust probes.
+    "src/v3/compiler/tests/integration/v4_emit_host_harness_test.rs",
+    // T-4.8 coordination substrate: decomposed WireContractFacts + CoordinationBind shape,
+    // with WIRECONTRACT-OBLIGATION-TABLE-T4.8 per-effect obligation rows.
+    "src/v3/compiler/tests/integration/v4_extdeps_coordination_dag_smoke_test.rs",
     // Wave-2-C2 / T-4.5: extdeps/file_system.dag pure resource model (Practice 11 companion).
     "src/v3/compiler/tests/integration/v4_extdeps_file_system_dag_smoke_test.rs",
     // T-4.16: `ConfigPatchRecord` / `config_patch_layer` consumer smoke on `black.dag`
     // (zero diagnostics; `BlackConfigPatch` materializes `FieldPatch<T>` fields).
     // SG-0 + INVARIANTS §P5(b) receipt.
     "src/v3/compiler/tests/integration/v4_extdeps_formatters_black_dag_smoke_test.rs",
-    // T-4.8 coordination substrate: decomposed WireContractFacts + CoordinationBind shape,
-    // with WIRECONTRACT-OBLIGATION-TABLE-T4.8 per-effect obligation rows.
-    "src/v3/compiler/tests/integration/v4_extdeps_coordination_dag_smoke_test.rs",
     // T-4.7 React framework substrate: `compile_to_dag` smoke on
     // `src/v4/extdeps/frameworks/react.dag` (zero module diagnostics).
     // SG-0 ratchet per INVARIANTS §P5(b) + typescript extdeps precedent.
     "src/v3/compiler/tests/integration/v4_extdeps_react_dag_smoke_test.rs",
-    // T-16-A+ TaskManager omni fixture: compile_to_dag smoke + SQL DDL projection receipt.
-    "src/v3/compiler/tests/integration/v4_test_fixture_task_manager_demo_smoke_test.rs",
     // T-21 IRT-1: incremental re-exec frontier (`src/v4/lens/affected_set.dag`);
     // `re_exec_frontier_from_diff` + mechanical reverification claim; SG-0 + INVARIANTS §P5(b).
     "src/v3/compiler/tests/integration/v4_lens_affected_set_dag_smoke_test.rs",
@@ -898,22 +899,26 @@ const EXPECTED_HAND_AUTHORED_TEST: &[&str] = &[
     // `manual_test_claim_for_manual_anchor` in `src/v4/lens/testgen.dag`; `src/v4/std/verification.dag`
     // for closed `TestClaim` schema only (no std present-key helper).
     "src/v3/compiler/tests/integration/v4_lens_testgen_dag_smoke_test.rs",
+    // P9 single-owner: corpus scan for `fn llvm_instruction_cost` under src/v4/ (replaces dissolved
+    // v4_lens_cost_dag_smoke_test.rs ratchet). SG-0 + INVARIANTS §P5(b) receipt.
+    "src/v3/compiler/tests/integration/v4_p9_llvm_instruction_cost_single_owner_test.rs",
     // T-33: parse ratchet on `src/v4/std/model_core.dag` — Ratified Q1 ModelCore carrier.
     // SG-0 + INVARIANTS §P5(b) receipt — row `v4_std_model_core_dag_smoke_test.rs` in INVARIANTS.md.
     "src/v3/compiler/tests/integration/v4_std_model_core_dag_smoke_test.rs",
+    // T-15: bin/main.dag execution + bootstrap fixpt stage1==stage2 harness (`t_15_self_host_fixed_point`).
+    "src/v3/compiler/tests/integration/v4_t15_self_host_fixed_point_harness_test.rs",
     // T-19/T-20 closeout ratchets over v4 testgen + bootstrap-infra parse surfaces.
     // SG-0 + INVARIANTS §P5(b) receipt; dissolves when the same checks are `.dag`
     // TestClaims or generated harness coverage.
     "src/v3/compiler/tests/integration/v4_test_bootstrap_infra_closeout_test.rs",
+    // T-16-A+ TaskManager omni fixture: compile_to_dag smoke + SQL DDL projection receipt.
+    "src/v3/compiler/tests/integration/v4_test_fixture_task_manager_demo_smoke_test.rs",
     // T-21/T-24: `workflow/ci.dag` Wave-0 selection consumes `RerunNodeSet` for TestClaim roster narrowing.
     // SG-0 + INVARIANTS §P5(b) receipt; dissolves when `.dag` TestClaim harness replaces probe.
     "src/v3/compiler/tests/integration/v4_workflow_ci_runner_dag_smoke_test.rs",
     // RELEASE_TODO §5 Phase 1a: `workflow/release.dag` + hand-synced release.yml (install.dag Phase 1b).
     // SG-0 + INVARIANTS §P5(b) receipt; dissolves when YamlStatic emission replaces host probes.
     "src/v3/compiler/tests/integration/v4_workflow_release_dag_smoke_test.rs",
-    // P9 single-owner: corpus scan for `fn llvm_instruction_cost` under src/v4/ (replaces dissolved
-    // v4_lens_cost_dag_smoke_test.rs ratchet). SG-0 + INVARIANTS §P5(b) receipt.
-    "src/v3/compiler/tests/integration/v4_p9_llvm_instruction_cost_single_owner_test.rs",
     // §1.8 gate #96 (`value_body_substrate_mirror_isomorphism_executable`):
     // CI-visible generated Rust `ValueBody` mirror vs `substrate.dag`
     // constructor isomorphism. Dissolves when `ValueBody` no longer has a

src/v3/compiler/tests/integration/v4_emit_host_harness_test.rs

@@ -0,0 +1,221 @@
+//! **Layer:** integration
+//!
+//! **W2 / joint spec** `compiler-spine-runtime-rung34-min-runner-interface-2026-05-30.md` §4.2:
+//! emit-host harness substrate (`emit_host.dag`, `host_run.dag`, `test_claim_falsification.dag`,
+//! `nat_semiring_rung34_eval.dag`) + executable boundary `tools/emit_host_runner`.
+//!
+//! **ROADMAP:** `ROADMAP.md` § **Nine lanes** row **T-PB-B** / `pb_rust_tests_outside_residual_zero`;
+//! **TASKS.md** T-38 / rung-4 host receipt path.
+//!
+//! **PR receipt (P5 Mechanism (b)):** this harness + matching `EXPECTED_HAND_AUTHORED_TEST`
+//! line in `sg0_census_test.rs` land in the same PR. **This PR (+1 census path):**
+//! `v4_emit_host_harness_test.rs` — behavior-driven `run_emit_host_rust` (compile + run fixture,
+//! `HostExit` Holds witness + five-byte stdout parse) plus **tokenize/parse** surface receipts
+//! for W2 `.dag` modules (not `str::contains` source probes per TESTING.md).
+//!
+//! **Dissolution trigger:** W3 populates `nat_semiring_rung34_runtime_value_rows`
+//! and wires `run_emit_host_rust` in `emit_host.dag` to invoke `tools/emit_host_runner` (removes
+//! `emit_host_transport_not_wired` on the Rust row); delete this file when rung-3/4 claims +
+//! generated harness replace hand-Rust probes (see `nat_semiring_rung34_eval.dag` roster comment).
+//!
+//! **TESTING.md:** substrate `.dag` eval remains hermetic (`run_emit_host_rust` → `Rejected` until
+//! W3/CI wiring); this test exercises the Rust transport the `.dag` row models, not substrate eval.
+
+use v3_compiler::parse_for_test;
+use v3_compiler::parse_surface::{SurfaceItem, SurfaceVariant};
+use v3_compiler::tokenize_for_test;
+
+const EMIT_HOST_DAG: &str = include_str!("../../../../v4/compiler/emit_host.dag");
+const EMIT_HOST_PATH: &str = "src/v4/compiler/emit_host.dag";
+const HOST_RUN_DAG: &str = include_str!("../../../../v4/std/host_run.dag");
+const HOST_RUN_PATH: &str = "src/v4/std/host_run.dag";
+const FALSIFICATION_DAG: &str = include_str!("../../../../v4/std/test_claim_falsification.dag");
+const FALSIFICATION_PATH: &str = "src/v4/std/test_claim_falsification.dag";
+const NAT_SEMIRING_RUNG34_EVAL_DAG: &str =
+    include_str!("../../../../v4/test/claim/workflow/nat_semiring_rung34_eval.dag");
+const NAT_SEMIRING_RUNG34_EVAL_PATH: &str =
+    "src/v4/test/claim/workflow/nat_semiring_rung34_eval.dag";
+
+/// Minimal fixture: five stdout bytes (MVP runtime value `5` alignment).
+const EMIT_HOST_FIXTURE_SOURCE: &str =
+    "fn main() { let _ = std::io::Write::write_all(&mut std::io::stdout(), &[0u8; 5]); }";
+
+fn parse_module(source: &str, path: &str) -> v3_compiler::parse_surface::SurfaceModule {
+    let tokens =
+        tokenize_for_test(source, path).unwrap_or_else(|e| panic!("{path}: tokenize: {e:?}"));
+    parse_for_test(&tokens, path).unwrap_or_else(|e| panic!("{path}: parse: {e:?}"))
+}
+
+fn surface_declares_fn(module: &v3_compiler::parse_surface::SurfaceModule, name: &str) -> bool {
+    module.items.iter().any(|item| match item {
+        SurfaceItem::Fn {
+            name: item_name, ..
+        }
+        | SurfaceItem::FnExternalBody {
+            name: item_name, ..
+        } => item_name == name,
+        _ => false,
+    })
+}
+
+fn surface_declares_type(module: &v3_compiler::parse_surface::SurfaceModule, name: &str) -> bool {
+    module.items.iter().any(|item| {
+        matches!(
+            item,
+            SurfaceItem::TypeSum { name: decl_name, .. }
+                | SurfaceItem::TypeRecord { name: decl_name, .. }
+                | SurfaceItem::TypeAlias { name: decl_name, .. }
+                | SurfaceItem::TypeAtom { name: decl_name, .. }
+                if decl_name == name
+        )
+    })
+}
+
+fn type_record_field_names(
+    module: &v3_compiler::parse_surface::SurfaceModule,
+    type_name: &str,
+) -> Vec<String> {
+    module
+        .items
+        .iter()
+        .find_map(|item| match item {
+            SurfaceItem::TypeRecord { name, fields, .. } if name == type_name => Some(
+                fields
+                    .iter()
+                    .map(|field| field.name.clone())
+                    .collect::<Vec<_>>(),
+            ),
+            _ => None,
+        })
+        .unwrap_or_else(|| panic!("{type_name}: missing type record"))
+}
+
+fn type_sum_variant<'a>(
+    module: &'a v3_compiler::parse_surface::SurfaceModule,
+    type_name: &str,
+    variant_name: &str,
+) -> &'a SurfaceVariant {
+    module
+        .items
+        .iter()
+        .find_map(|item| match item {
+            SurfaceItem::TypeSum { name, variants, .. } if name == type_name => {
+                variants.iter().find(|variant| variant.name == variant_name)
+            }
+            _ => None,
+        })
+        .unwrap_or_else(|| panic!("missing `{type_name}.{variant_name}` variant"))
+}
+
+#[test]
+fn emit_host_runner_rust_row_builds_runs_and_parses_stdout() {
+    let work_dir = emit_host_runner::default_work_dir(&format!(
+        "gunbc_v4_emit_host_harness_{}",
+        std::process::id()
+    ));
+    let inputs = emit_host_runner::EmitHostFixtureInputs {
+        claim_input_root: "w2_harness_claim_input".to_string(),
+        expected_eval_root: "w2_harness_expected_eval".to_string(),
+    };
+    let receipt =
+        emit_host_runner::run_emit_host_rust(EMIT_HOST_FIXTURE_SOURCE, &inputs, &work_dir)
+            .expect("run_emit_host_rust");
+    assert!(
+        receipt.exit.exit_holds(),
+        "expected successful host exit (Holds witness), got {:?}",
+        receipt.exit
+    );
+    assert!(
+        emit_host_runner::host_logical_run_from_exit(&receipt.exit, receipt.stdout_bytes.clone())
+            .is_some(),
+        "logical_run projection requires Holds exit"
+    );
+    emit_host_runner::runtime_value_parse_rust(&receipt.stdout_bytes)
+        .expect("runtime_value_parse_rust on fixture stdout");
+}
+
+#[test]
+fn v4_host_run_dag_tokenizes_and_parses_logical_run_carrier() {
+    let module = parse_module(HOST_RUN_DAG, HOST_RUN_PATH);
+    assert!(
+        surface_declares_type(&module, "HostRunStdout"),
+        "{HOST_RUN_PATH}: HostRunStdout carrier"
+    );
+    assert!(
+        surface_declares_type(&module, "HostLogicalRun"),
+        "{HOST_RUN_PATH}: HostLogicalRun carrier"
+    );
+    assert_eq!(
+        type_record_field_names(&module, "HostLogicalRun"),
+        vec!["stdout".to_string()],
+        "{HOST_RUN_PATH}: success-only logical run (no nested Witness)"
+    );
+    assert!(
+        surface_declares_fn(&module, "host_logical_run_from_exit"),
+        "{HOST_RUN_PATH}: host_logical_run_from_exit"
+    );
+}
+
+#[test]
+fn v4_falsification_dag_tokenizes_and_parses_execution_evidence() {
+    let module = parse_module(FALSIFICATION_DAG, FALSIFICATION_PATH);
+    assert!(
+        surface_declares_type(&module, "FalsificationReceipt"),
+        "{FALSIFICATION_PATH}: FalsificationReceipt"
+    );
+    let receipt_fields = type_record_field_names(&module, "FalsificationReceipt");
+    assert!(
+        receipt_fields.contains(&"subject".to_string()),
+        "{FALSIFICATION_PATH}: FalsificationReceipt.subject"
+    );
+    for variant in ["Host", "Interpreter", "EvidenceNone"] {
+        let _ = type_sum_variant(&module, "ExecutionEvidence", variant);
+    }
+}
+
+#[test]
+fn v4_emit_host_dag_tokenizes_and_parses_fail_closed_surface() {
+    let module = parse_module(EMIT_HOST_DAG, EMIT_HOST_PATH);
+    for name in [
+        "run_emit_host_rust",
+        "run_emit_host",
+        "host_exit_failure_outcome",
+        "run_test_claim_emit_vs_eval_for_claim",
+        "run_test_claim_emit_vs_eval",
+    ] {
+        assert!(
+            surface_declares_fn(&module, name),
+            "{EMIT_HOST_PATH}: missing fn {name}"
+        );
+    }
+    assert!(
+        module.items.iter().any(|item| matches!(
+            item,
+            SurfaceItem::Data { name, .. } if name == "emit_host_transport_not_wired"
+        )),
+        "{EMIT_HOST_PATH}: transport_not_wired symbol"
+    );
+}
+
+#[test]
+fn v4_nat_semiring_rung_gate_dag_tokenizes_and_parses_empty_roster_gates() {
+    let module = parse_module(NAT_SEMIRING_RUNG34_EVAL_DAG, NAT_SEMIRING_RUNG34_EVAL_PATH);
+    for name in [
+        "nat_semiring_rung34_report_has_evidence",
+        "nat_semiring_rung3_gate",
+        "nat_semiring_rung4_gate",
+        "run_nat_semiring_rung34_eval",
+    ] {
+        assert!(
+            surface_declares_fn(&module, name),
+            "{NAT_SEMIRING_RUNG34_EVAL_PATH}: missing fn {name}"
+        );
+    }
+    assert!(
+        module.items.iter().any(|item| matches!(
+            item,
+            SurfaceItem::Data { name, .. } if name == "nat_semiring_rung34_runtime_value_rows"
+        )),
+        "{NAT_SEMIRING_RUNG34_EVAL_PATH}: empty runtime roster"
+    );
+}