[test do not merge] snapshot golden tests

.github/workflows/RegenSnapshotGoldens.yml

@@ -0,0 +1,92 @@
+# yaml-language-server: $schema=https://json.schemastore.org/github-workflow.json
+
+name: Regenerate Snapshot Goldens
+
+on:
+  pull_request:
+    types: [labeled]
+
+permissions:
+  contents: read
+  pull-requests: read
+
+defaults:
+  run:
+    shell: bash
+
+jobs:
+  # Build guests once, upload as artifacts for the regen jobs to
+  # download. Mirrors `build-guests` in `ValidatePullRequest.yml`.
+  build-guests:
+    if: github.event.label.name == 'regen-goldens'
+    strategy:
+      fail-fast: false
+      matrix:
+        config: [debug]
+    uses: ./.github/workflows/dep_build_guests.yml
+    secrets: inherit
+    with:
+      docs_only: "false"
+      config: ${{ matrix.config }}
+
+  regen:
+    if: github.event.label.name == 'regen-goldens'
+    needs: [build-guests]
+    timeout-minutes: 30
+    strategy:
+      fail-fast: false
+      matrix:
+        hypervisor: ['hyperv-ws2025', mshv3, kvm]
+        cpu: [amd, intel]
+    runs-on: ${{ fromJson(
+        format('["self-hosted", "{0}", "X64", "1ES.Pool=hld-{1}-{2}", "JobId=regen-goldens-{3}-{4}-{5}-{6}"]',
+          matrix.hypervisor == 'hyperv-ws2025' && 'Windows' || 'Linux',
+          matrix.hypervisor == 'hyperv-ws2025' && 'win2025' || matrix.hypervisor == 'mshv3' && 'azlinux3-mshv' || matrix.hypervisor,
+          matrix.cpu,
+          matrix.hypervisor,
+          github.run_id,
+          github.run_number,
+          github.run_attempt)) }}
+    steps:
+      - uses: actions/checkout@v6
+
+      - uses: hyperlight-dev/ci-setup-workflow@v1.9.0
+        with:
+          rust-toolchain: "1.89"
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Fix cargo home permissions
+        if: runner.os == 'Linux'
+        run: |
+          sudo chown -R $(id -u):$(id -g) /opt/cargo || true
+
+      - name: Rust cache
+        uses: Swatinem/rust-cache@v2
+        with:
+          shared-key: "${{ runner.os }}-debug"
+          cache-on-failure: "true"
+
+      - name: Download Rust guests
+        uses: actions/download-artifact@v8
+        with:
+          name: rust-guests-debug
+          path: src/tests/rust_guests/bin/debug/
+
+      - name: Run regen
+        env:
+          HYPERLIGHT_REGEN_GOLDENS: "1"
+        run: |
+          cargo test -p hyperlight-host --lib \
+            sandbox::snapshot::golden_tests::golden_regen \
+            -- --nocapture
+
+      - name: Upload regenerated fixtures
+        uses: actions/upload-artifact@v4
+        with:
+          name: goldens-${{ matrix.hypervisor }}-${{ matrix.cpu }}
+          path: src/hyperlight_host/tests/snapshot_goldens/fixtures/*.hls
+          # Fail loudly if the regen produced nothing rather than
+          # silently uploading an empty artifact.
+          if-no-files-found: error
+          retention-days: 14