diff --git a/.github/workflows/silicon-nightly.yml b/.github/workflows/silicon-nightly.yml
index 3bd680fbc5..9a9ccbc567 100644
--- a/.github/workflows/silicon-nightly.yml
+++ b/.github/workflows/silicon-nightly.yml
@@ -101,6 +101,8 @@ jobs:
     timeout-minutes: 90
     steps:
       - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1  # v7.0.1
+      - name: cargo_step.sh falsifier (ENV-vs-CODE instrument)
+        run: bash scripts/cargo_step.sh --self-test
       - name: Put the runner's Rust toolchain on PATH
         run: echo "$HOME/.cargo/bin" >> "$GITHUB_PATH"
       # THE ARCH-SENSITIVE SUBSET, not the whole suite. Five legs of a full
@@ -109,7 +111,8 @@ jobs:
       - name: SIMD and numeric paths (x86_64, widest vectors)
         run: |
           set -euo pipefail
-          nice -n 19 cargo test -p aprender-compute --release --lib
+          bash scripts/cargo_step.sh 'x86_64 SIMD: aprender-compute' -- \
+              nice -n 19 cargo test -p aprender-compute --release --lib
           # `aprender-primitives` does not exist and never has. It was invented by
           # this file (#2772) and killed BOTH legs with `package ID specification
           # ... did not match any packages`, exit 101, every night since
@@ -118,7 +121,8 @@ jobs:
           # (10 files with target_arch/target_feature, after aprender-compute's
           # 110). scripts/check_workflow_cargo_packages.sh makes the class
           # unrepeatable. YOGA-NIGHTLY-001 R-8.
-          nice -n 19 cargo test -p aprender-core --release --lib
+          bash scripts/cargo_step.sh 'x86_64 SIMD: aprender-core' -- \
+              nice -n 19 cargo test -p aprender-core --release --lib
 
   aarch64-cuda-sm121:
     if: ${{ github.event_name != 'workflow_dispatch' || inputs.axis == 'all' || inputs.axis == 'aarch64-cuda-sm121' }}
@@ -138,6 +142,8 @@ jobs:
     timeout-minutes: 90
     steps:
       - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1  # v7.0.1
+      - name: cargo_step.sh falsifier (ENV-vs-CODE instrument)
+        run: bash scripts/cargo_step.sh --self-test
       - name: Put the runner's Rust toolchain on PATH
         run: echo "$HOME/.cargo/bin" >> "$GITHUB_PATH"
       # ASK THE BOX, NEVER THE LABEL. A label says what we intended; nvidia-smi
@@ -163,7 +169,8 @@ jobs:
       - name: NEON and numeric paths (aarch64)
         run: |
           set -euo pipefail
-          nice -n 19 cargo test -p aprender-compute --release --lib
+          bash scripts/cargo_step.sh 'aarch64 SIMD: aprender-compute' -- \
+              nice -n 19 cargo test -p aprender-compute --release --lib
           # `aprender-primitives` does not exist and never has. It was invented by
           # this file (#2772) and killed BOTH legs with `package ID specification
           # ... did not match any packages`, exit 101, every night since
@@ -172,7 +179,8 @@ jobs:
           # (10 files with target_arch/target_feature, after aprender-compute's
           # 110). scripts/check_workflow_cargo_packages.sh makes the class
           # unrepeatable. YOGA-NIGHTLY-001 R-8.
-          nice -n 19 cargo test -p aprender-core --release --lib
+          bash scripts/cargo_step.sh 'aarch64 SIMD: aprender-core' -- \
+              nice -n 19 cargo test -p aprender-core --release --lib
 
       # AN AXIS NAMED `cuda` MUST INVOKE CUDA (YOGA-NIGHTLY-001 R-6).
       #
diff --git a/docs/roadmaps/roadmap.yaml b/docs/roadmaps/roadmap.yaml
index 343c44c90b..61c49f889d 100644
--- a/docs/roadmaps/roadmap.yaml
+++ b/docs/roadmaps/roadmap.yaml
@@ -17783,3 +17783,21 @@ roadmap:
   labels:
   - kind:code
   notes: null
+- id: PMAT-3236
+  github_issue: null
+  item_type: task
+  title: 'Silicon Nightly reported a vanished dep-info file as a SIMD failure — route its cargo through the ENV/CODE classifier'
+  status: inprogress
+  priority: medium
+  assigned_to: null
+  created: 2026-09-14T20:25:00Z
+  updated: 2026-09-14T20:25:00Z
+  spec: docs/specifications/APR-RELEASE-001-train-and-build-kaizen.md
+  acceptance_criteria: []
+  phases: []
+  subtasks: []
+  estimated_effort: null
+  labels:
+  - kind:code
+  notes: 'cargo_step.sh (#3241) classifies dep-info ENOENT as ENV and was wired to
+    book.yml only; 5 of 75 cargo invocation lines across all workflows were covered'