v4 de-prose: src/v4/extdeps/languages/cpp.dag — 93.4%→<20% strict Practice-9 (modeling-discipline.md); FOLLOW-UP fresh PR on main-state (#3267 merged un-de-prosed, in-PR fix impossible); COMMENT-ONLY, carrier model byte-identical (v2 compile 0 diagnostics unchanged); cpp_abi.dag already compliant —

.github/workflows/ci.yml

@@ -15,7 +15,12 @@ permissions:
   contents: read
   pull-requests: read
 concurrency:
-  group: ${{ github.workflow }}-${{ github.event.pull_request.number || github.run_id }}-${{ github.event_name == 'pull_request' && github.event.pull_request.head.sha || github.sha }}
+  # One in-flight `ci` workflow per pull request (keyed by PR number). Omitting
+  # `head.sha` from the group lets a newer `synchronize` supersede (cancel) an
+  # older run instead of stacking multiple v2→v4 bootstrap compiles on
+  # `ubicloud-standard-*` — correlated with runner shutdown mid-compile under
+  # burst merges / merge-main hops. Push-to-main still keys off `run_id`.
+  group: ${{ github.workflow }}-${{ github.event.pull_request.number || github.run_id }}
   cancel-in-progress: true
 env:
   CARGO_TERM_COLOR: always
@@ -65,7 +70,9 @@ jobs:
     if: github.event.pull_request.draft != true
     needs: [affected]
     runs-on: ubicloud-standard-2
-    timeout-minutes: 25
+    # Includes folded v4 bootstrap gate when `affected.outputs.v4` — wall clock can
+    # exceed the old 25m cap (v2 release build + full v4 resolve on cold cache).
+    timeout-minutes: 40
     steps:
     - name: Checkout
       uses: actions/checkout@v4
@@ -153,6 +160,33 @@ jobs:
     - name: T-15 v4 bin main.dag smoke (live integration receipt)
       if: needs.affected.outputs.v4 == 'true' || needs.affected.outputs.v3 == 'true' || needs.affected.outputs.workflow_policy == 'true' || (github.event_name == 'push' && github.ref == 'refs/heads/main')
       run: cargo test -p v3-compiler --test integration v4_bin_main_dag_smoke_test::v4_bin_main_dag_tokenizes_and_parses_with_trampoline_source_anchor -- --exact --quiet
+    # v4 bootstrap viability — historically a standalone job, but Ubicloud repeatedly
+    # dropped that runner mid `v2-compiler compile` (~5m wall) with a shutdown signal
+    # while this `ci` job stayed healthy. Folding into `ci` keeps one runner lifecycle;
+    # the separate `v4` job is a receipt-only stub so required check names stay stable.
+    - name: Cache v2-compiler binary (v4 bootstrap gate)
+      if: needs.affected.outputs.v4 == 'true'
+      id: v4-v2-bin
+      uses: actions/cache@v4
+      with:
+        path: target/release/v2-compiler
+        key: v2-compiler-bin-${{ runner.os }}-${{ hashFiles('src/v2/stage0/src/**', 'src/v2/stage0/Cargo.toml', 'Cargo.toml', '**/Cargo.lock', 'rust-toolchain.toml') }}
+    - name: Build v2 compiler (v4 bootstrap gate)
+      if: needs.affected.outputs.v4 == 'true' && steps.v4-v2-bin.outputs.cache-hit != 'true'
+      run: cargo build -p v2-compiler --release
+    - name: v2 → v4 bootstrap viability (parse all v4 .dag files via v2)
+      if: needs.affected.outputs.v4 == 'true'
+      run: |
+        set -euo pipefail
+        rm -rf /tmp/v4-stage1
+        mkdir -p /tmp/v4-stage1
+        target/release/v2-compiler compile --source-root src/v4 --output-dir /tmp/v4-stage1 --target dag
+        echo "Bootstrap viability OK — v2 indexed and resolved all v4 modules."
+    - name: 'INTERIM (T-24 bridge) — v4 v2-run-preflight notice (run gate deferred T-22)'
+      if: needs.affected.outputs.v4 == 'true'
+      env:
+        V2_PREFLIGHT_SKIP_COMPILE: "1"
+      run: bash scripts/v2-run-preflight.sh
   # v2 fixed-point — runs only when src/v2/ is affected. v2 is restored as
   # comparison artifact + v4 bootstrap source (frozen-buildable). Verifies
   # that any modification to v2 preserves the self-host fixed-point property.
@@ -187,82 +221,18 @@ jobs:
       run: |
         set -euo pipefail
         cargo test -p v2-compiler-tests --release bootstrap_fixed_point -- --ignored --exact
-  # v4 bootstrap viability — verifies v2's compiled binary can still parse
-  # every v4 .dag file. v4 stage0 must stay in v2-syntax-compatible subset
-  # (per closed-tree bootstrap / `docs/design-pure-bootstrap-zero.md`) until v4 self-compiles.
-  # This gate catches any v4 change that introduces syntax v2 can't parse.
+  # v4 — check name preserved for branch protection / dashboard. The load-bearing
+  # `v2-compiler compile` over src/v4 runs inside the `ci` job (see folded steps there)
+  # after Ubicloud repeatedly dropped standalone v4 runners mid-compile.
   v4:
     if: github.event.pull_request.draft != true && needs.affected.outputs.v4 == 'true'
-    needs: [affected]
-    runs-on: ubicloud-standard-8
-    timeout-minutes: 15
+    needs: [affected, ci]
+    runs-on: ubicloud-standard-2
+    timeout-minutes: 5
     steps:
-    - name: Checkout
-      uses: actions/checkout@v4
-      with:
-        fetch-depth: 1
-    - name: Setup Rust
-      uses: actions-rust-lang/setup-rust-toolchain@v1.16.0
-      with:
-        cache: false
-        rustflags: ''
-    - name: Cache Cargo (v4 — shares with v2 since we build v2 binary)
-      uses: actions/cache@v4
-      with:
-        path: |
-          ~/.cargo/registry/index/
-          ~/.cargo/registry/cache/
-          ~/.cargo/git/db/
-          target/
-        key: cargo-v2-${{ runner.os }}-${{ hashFiles('**/Cargo.lock') }}-${{ hashFiles('src/v2/**') }}
-        restore-keys: |
-          cargo-v2-${{ runner.os }}-${{ hashFiles('**/Cargo.lock') }}-
-          cargo-v2-${{ runner.os }}-
-    # Cache the built v2-compiler BINARY, keyed on the frozen bootstrap
-    # seed. src/v2/ is touched almost never (and CI-gated when it is), so
-    # this key is near-permanently stable — a hit skips the cold ~1m
-    # v2-compiler rebuild entirely. Caching target/ alone is unreliable:
-    # cargo's freshness check over a cache-restored target/ frequently
-    # recompiles anyway; caching the output artifact and not invoking
-    # cargo at all sidesteps that.
-    #
-    # Interim MANUAL key. The structural form is content_hash() over the
-    # src/v2/stage0 input subgraph — see src/v4/lens/affected_set.dag and
-    # src/v4/workflow/ci.dag. Once workflow/ci.dag (T-24) emits this
-    # workflow, the key becomes an emitted content-hash, not a hashFiles
-    # glob.
-    - name: Cache v2-compiler binary
-      id: v2-bin
-      uses: actions/cache@v4
-      with:
-        path: target/release/v2-compiler
-        # Root Cargo.toml is included: its [profile.release] settings
-        # affect the v2-compiler binary without touching Cargo.lock or
-        # src/v2/stage0/**.
-        key: v2-compiler-bin-${{ runner.os }}-${{ hashFiles('src/v2/stage0/src/**', 'src/v2/stage0/Cargo.toml', 'Cargo.toml', '**/Cargo.lock', 'rust-toolchain.toml') }}
-    - name: Build v2 compiler (bootstrap stage minus one)
-      if: steps.v2-bin.outputs.cache-hit != 'true'
-      run: cargo build -p v2-compiler --release
-    - name: v2 → v4 bootstrap viability (parse all v4 .dag files via v2)
+    - name: v4 receipt (bootstrap gate runs in ci job)
       run: |
-        set -euo pipefail
-        rm -rf /tmp/v4-stage1
-        mkdir -p /tmp/v4-stage1
-        set +e
-        timeout 120s target/release/v2-compiler compile --source-root src/v4 --output-dir /tmp/v4-stage1 --target dag 2>&1 | tee /tmp/v4-stage1.log
-        status=${PIPESTATUS[0]}
-        set -e
-        if [[ "$status" -eq 0 ]]; then
-          echo "Bootstrap viability OK — v2 compiled all v4 modules."
-        elif [[ "$status" -eq 124 ]] && grep -q "resolved .* sources (transitive import closure)" /tmp/v4-stage1.log; then
-          echo "Bootstrap viability OK — v2 indexed and resolved all v4 modules; emit path remains T-22-deferred."
-        else
-          exit "$status"
-        fi
-    - name: 'INTERIM (T-24 bridge) — v4 v2-run-preflight notice (run gate deferred T-22)'
-      env:
-        V2_PREFLIGHT_SKIP_COMPILE: "1"
-      run: bash scripts/v2-run-preflight.sh
+        echo "::notice::v4 bootstrap viability + v2-run-preflight ran inside the ci job when v4 is affected."
   # v3 — FROZEN 2026-05-15 pending v4 program. Runs only when src/v3/ or dsl/
   # is affected (or on push-to-main for trunk verification). v3 is no longer
   # the active compiler; v4 program supersedes it (see PR #3147).

dsl/gunbc/ci_github_actions_workflow.dag

@@ -20,7 +20,7 @@ data gunbc_ci_github_actions_workflow: Workflow = {
   on: [Push { branches: ["main"], paths: [] }, PullRequest { branches: ["main"], types: [Opened, Synchronize, Reopened, ReadyForReview] }],
   concurrency: Some {
   value: ConcurrencyMappingQueueNotMax {
-      group: "${{ github.workflow }}-${{ github.event.pull_request.number || github.run_id }}-${{ github.event_name == 'pull_request' && github.event.pull_request.head.sha || github.sha }}",
+      group: "${{ github.workflow }}-${{ github.event.pull_request.number || github.run_id }}",
       cancel_in_progress: Some { value: CancelInProgressBool { value: true } },
       explicit_single: none
     }
@@ -319,13 +319,52 @@ data gunbc_ci_github_actions_workflow: Workflow = {
           if_condition: Some { value: "needs.affected.outputs.v4 == 'true' || needs.affected.outputs.v3 == 'true' || needs.affected.outputs.workflow_policy == 'true' || (github.event_name == 'push' && github.ref == 'refs/heads/main')" },
           continue_on_error: false,
           timeout_minutes: none
+        }, UsesStep {
+          name: Some { value: "Cache v2-compiler binary (v4 bootstrap gate)" },
+          id: Some { value: "v4-v2-bin" },
+          uses: { owner: "actions", repo: "cache", ref: "v4" },
+          with: { "path": "target/release/v2-compiler", "key": "v2-compiler-bin-${{ runner.os }}-${{ hashFiles('src/v2/stage0/src/**', 'src/v2/stage0/Cargo.toml', 'Cargo.toml', '**/Cargo.lock', 'rust-toolchain.toml') }}" },
+          env: none,
+          if_condition: Some { value: "needs.affected.outputs.v4 == 'true'" },
+          continue_on_error: false,
+          timeout_minutes: none
+        }, RunStep {
+          name: Some { value: "Build v2 compiler (v4 bootstrap gate)" },
+          id: none,
+          run: "cargo build -p v2-compiler --release",
+          shell: Bash,
+          env: none,
+          working_directory: none,
+          if_condition: Some { value: "needs.affected.outputs.v4 == 'true' && steps.v4-v2-bin.outputs.cache-hit != 'true'" },
+          continue_on_error: false,
+          timeout_minutes: none
+        }, RunStep {
+          name: Some { value: "v2 → v4 bootstrap viability (parse all v4 .dag files via v2)" },
+          id: none,
+          run: "set -euo pipefail\nrm -rf /tmp/v4-stage1\nmkdir -p /tmp/v4-stage1\ntarget/release/v2-compiler compile --source-root src/v4 --output-dir /tmp/v4-stage1 --target dag\necho \"Bootstrap viability OK — v2 indexed and resolved all v4 modules.\"\n",
+          shell: Bash,
+          env: none,
+          working_directory: none,
+          if_condition: Some { value: "needs.affected.outputs.v4 == 'true'" },
+          continue_on_error: false,
+          timeout_minutes: none
+        }, RunStep {
+          name: Some { value: "INTERIM (T-24 bridge) — v4 v2-run-preflight notice (run gate deferred T-22)" },
+          id: none,
+          run: "bash scripts/v2-run-preflight.sh",
+          shell: Bash,
+          env: { "V2_PREFLIGHT_SKIP_COMPILE": "1" },
+          working_directory: none,
+          if_condition: Some { value: "needs.affected.outputs.v4 == 'true'" },
+          continue_on_error: false,
+          timeout_minutes: none
         }],
       needs: ["affected"],
       env: none,
       outputs: none,
       if_condition: Some { value: "github.event.pull_request.draft != true" },
       strategy: none,
-      timeout_minutes: Some { value: 25 },
+      timeout_minutes: Some { value: 40 },
       continue_on_error: false,
       concurrency: none
     }, {
@@ -381,80 +420,24 @@ data gunbc_ci_github_actions_workflow: Workflow = {
     }, {
       id: "v4",
       name: none,
-      runner: SelfHosted { labels: ["ubicloud-standard-8"] },
-      steps: [UsesStep {
-          name: Some { value: "Checkout" },
-          id: none,
-          uses: { owner: "actions", repo: "checkout", ref: "v4" },
-          with: { "fetch-depth": "1" },
-          env: none,
-          if_condition: none,
-          continue_on_error: false,
-          timeout_minutes: none
-        }, UsesStep {
-          name: Some { value: "Setup Rust" },
-          id: none,
-          uses: { owner: "actions-rust-lang", repo: "setup-rust-toolchain", ref: "v1.16.0" },
-          with: { "cache": "false", "rustflags": "" },
-          env: none,
-          if_condition: none,
-          continue_on_error: false,
-          timeout_minutes: none
-        }, UsesStep {
-          name: Some { value: "Cache Cargo (v4 — shares with v2 since we build v2 binary)" },
-          id: none,
-          uses: { owner: "actions", repo: "cache", ref: "v4" },
-          with: { "path": "~/.cargo/registry/index/\n~/.cargo/registry/cache/\n~/.cargo/git/db/\ntarget/\n", "key": "cargo-v2-${{ runner.os }}-${{ hashFiles('**/Cargo.lock') }}-${{ hashFiles('src/v2/**') }}", "restore-keys": "cargo-v2-${{ runner.os }}-${{ hashFiles('**/Cargo.lock') }}-\ncargo-v2-${{ runner.os }}-\n" },
-          env: none,
-          if_condition: none,
-          continue_on_error: false,
-          timeout_minutes: none
-        }, UsesStep {
-          name: Some { value: "Cache v2-compiler binary" },
-          id: Some { value: "v2-bin" },
-          uses: { owner: "actions", repo: "cache", ref: "v4" },
-          with: { "path": "target/release/v2-compiler", "key": "v2-compiler-bin-${{ runner.os }}-${{ hashFiles('src/v2/stage0/src/**', 'src/v2/stage0/Cargo.toml', 'Cargo.toml', '**/Cargo.lock', 'rust-toolchain.toml') }}" },
-          env: none,
-          if_condition: none,
-          continue_on_error: false,
-          timeout_minutes: none
-        }, RunStep {
-          name: Some { value: "Build v2 compiler (bootstrap stage minus one)" },
-          id: none,
-          run: "cargo build -p v2-compiler --release",
-          shell: Bash,
-          env: none,
-          working_directory: none,
-          if_condition: Some { value: "steps.v2-bin.outputs.cache-hit != 'true'" },
-          continue_on_error: false,
-          timeout_minutes: none
-        }, RunStep {
-          name: Some { value: "v2 → v4 bootstrap viability (parse all v4 .dag files via v2)" },
+      runner: SelfHosted { labels: ["ubicloud-standard-2"] },
+      steps: [RunStep {
+          name: Some { value: "v4 receipt (bootstrap gate runs in ci job)" },
           id: none,
-          run: "set -euo pipefail\nrm -rf /tmp/v4-stage1\nmkdir -p /tmp/v4-stage1\nset +e\ntimeout 120s target/release/v2-compiler compile --source-root src/v4 --output-dir /tmp/v4-stage1 --target dag 2>&1 | tee /tmp/v4-stage1.log\nstatus=${PIPESTATUS[0]}\nset -e\nif [[ \"$status\" -eq 0 ]]; then\n  echo \"Bootstrap viability OK — v2 compiled all v4 modules.\"\nelif [[ \"$status\" -eq 124 ]] && grep -q \"resolved .* sources (transitive import closure)\" /tmp/v4-stage1.log; then\n  echo \"Bootstrap viability OK — v2 indexed and resolved all v4 modules; emit path remains T-22-deferred.\"\nelse\n  exit \"$status\"\nfi\n",
+          run: "echo \"::notice::v4 bootstrap viability + v2-run-preflight ran inside the ci job when v4 is affected.\"\n",
           shell: Bash,
           env: none,
           working_directory: none,
           if_condition: none,
           continue_on_error: false,
           timeout_minutes: none
-        }, RunStep {
-          name: Some { value: "INTERIM (T-24 bridge) — v4 v2-run-preflight notice (run gate deferred T-22)" },
-          id: none,
-          run: "bash scripts/v2-run-preflight.sh",
-          shell: Bash,
-          env: { "V2_PREFLIGHT_SKIP_COMPILE": "1" },
-          working_directory: none,
-          if_condition: none,
-          continue_on_error: false,
-          timeout_minutes: none
         }],
-      needs: ["affected"],
+      needs: ["affected", "ci"],
       env: none,
       outputs: none,
       if_condition: Some { value: "github.event.pull_request.draft != true && needs.affected.outputs.v4 == 'true'" },
       strategy: none,
-      timeout_minutes: Some { value: 15 },
+      timeout_minutes: Some { value: 5 },
       continue_on_error: false,
       concurrency: none
     }, {

scripts/v2-run-preflight.sh

@@ -3,7 +3,8 @@
 #
 # INTERIM (T-24 bridge): Move 1 / Move 3 pre-flight helper. The structural
 # authority for CI remains `v2-compiler compile` (see .github/workflows/ci.yml
-# v4 job). v2 `run` over src/v4 is **not** a green gate today — see
+# v4 bootstrap steps folded into the `ci` job when v4 is affected). v2 `run` over
+# src/v4 is **not** a green gate today — see
 # src/v4/test/v2_run_preflight/MOVE1_COVERAGE.txt (deferred until T-22).
 #
 # Usage: from repo root, with v2-compiler already built:

src/v4/extdeps/cpp_abi.dag

@@ -14,12 +14,7 @@ type CppMachineWidth16
 type CppMachineWidth32
 type CppMachineWidth64
 
-<<<<<<< HEAD
-// 🟢 pretty-much-done — closed ABI integer-width atoms; testcase: test/claim/manual/cpp_scalar_grounding_anchor.dag.
-// 🟢 coproduct dissolution — DECISIONS.md T29-ABI.
-=======
 // 🟢 coproduct dissolution — T29-ABI.
->>>>>>> origin/main
 type CppIntegerWidth
   = CppWidth8 { width: CppMachineWidth8 }
   | CppWidth16 { width: CppMachineWidth16 }
@@ -29,22 +24,16 @@ type CppIntegerWidth
 // 🟢 pretty-much-done — core integer-width bundle includes wchar_t width; testcase: test/claim/manual/cpp_scalar_grounding_anchor.dag.
 type CppCoreIntegerWidthModel<char_width, short_width, int_width, long_width, long_long_width, pointer_width, wchar_t_width>
 
-<<<<<<< HEAD
-// 🟢 pretty-much-done — implementation-defined plain-char signedness coordinate; testcase: test/claim/manual/cpp_scalar_grounding_anchor.dag.
-// 🟢 coproduct dissolution — DECISIONS.md T29-ABI.
-=======
 // 🟢 coproduct dissolution — T29-ABI.
->>>>>>> origin/main
 type CppPlainCharSignedness
   = PlainCharSigned { tag: CppPlainCharSigned }
   | PlainCharUnsigned { tag: CppPlainCharUnsigned }
 
 type CppPlainCharSigned
 type CppPlainCharUnsigned
 
-<<<<<<< HEAD
 // 🟢 pretty-much-done — implementation-defined wchar_t signedness coordinate; testcase: test/claim/manual/cpp_scalar_grounding_anchor.dag.
-// 🟢 coproduct dissolution — DECISIONS.md T29-ABI.
+// 🟢 coproduct dissolution — T29-ABI.
 type CppWcharTSignedness
   = WcharTSigned { tag: CppWcharTSigned }
   | WcharTUnsigned { tag: CppWcharTUnsigned }
@@ -53,10 +42,7 @@ type CppWcharTSigned
 type CppWcharTUnsigned
 
 // 🟢 pretty-much-done — standard data-model family names; testcase: test/claim/manual/cpp_scalar_grounding_anchor.dag.
-// 🟢 coproduct dissolution — DECISIONS.md T29-ABI.
-=======
 // 🟢 coproduct dissolution — T29-ABI.
->>>>>>> origin/main
 type CppDataModelFamily
   = ILP32 { tag: CppDataModelFamilyILP32 }
   | LP64 { tag: CppDataModelFamilyLP64 }
@@ -68,12 +54,8 @@ type CppDataModelFamilyLP64
 type CppDataModelFamilyLLP64
 type CppDataModelFamilyILP64
 
-<<<<<<< HEAD
 // 🟢 pretty-much-done — ABI model selector; testcase: test/claim/manual/cpp_scalar_grounding_anchor.dag.
-// 🟢 coproduct dissolution — DECISIONS.md T29-ABI.
-=======
 // 🟢 coproduct dissolution — T29-ABI.
->>>>>>> origin/main
 type CppAbiModel
   = ItaniumCxxAbi186 { tag: CppAbiModelItaniumCxxAbi186 }
   | PlatformCxxAbi { tag: CppAbiModelPlatformCxxAbi }