@@ -79,6 +79,15 @@ jobs:
     needs: changes
     if: needs.changes.outputs.code-changed == 'true'
     name: ${{ matrix.name }}
+    # Each native build shares one per-job, per-arch Blacksmith sticky disk
+    # across every run. Overlapping runs clone the same snapshot and re-commit
+    # wholesale, so a later run overwrites the deps another run just pinned and
+    # both rebuild from scratch. Serialise runs of the same matrix entry (queue,
+    # don't cancel) so the pinned deps survive and stay warm. The key is per
+    # matrix.name because each entry already has its own disk.
+    concurrency:
+      group: build-native-${{ matrix.name }}
+      cancel-in-progress: false
     permissions:
       actions: write
       contents: read