Optimized image build time

.gitea/workflows/build-ci-image.yml

@@ -37,15 +37,30 @@ jobs:
             -u "$username" \
             --password-stdin
 
-      - name: Build CI image
+      - name: Build and push CI image
+        env:
+          DOCKER_BUILDKIT: 1
         run: |
-          docker build \
-            --build-arg BASE_IMAGE=catthehacker/ubuntu:act-latest \
-            --build-arg LLVM_VERSION=22 \
-            --build-arg MESON_VERSION=latest \
-            -t "$REGISTRY_IMAGE:latest" \
-            -f Dockerfile .
-
-      - name: Push CI image
-        run: |
-          docker push "$REGISTRY_IMAGE:latest"
+          if docker buildx version >/dev/null 2>&1; then
+            docker buildx create --use --name evol-testbed-builder || docker buildx use evol-testbed-builder
+            docker buildx build \
+              --build-arg BASE_IMAGE=catthehacker/ubuntu:act-latest \
+              --build-arg LLVM_VERSION=22 \
+              --build-arg MESON_VERSION=latest \
+              --cache-from type=registry,ref="$REGISTRY_IMAGE:buildcache" \
+              --cache-to type=registry,ref="$REGISTRY_IMAGE:buildcache",mode=max \
+              --tag "$REGISTRY_IMAGE:latest" \
+              --file Dockerfile \
+              --push \
+              .
+          else
+            echo "docker buildx is unavailable; falling back to uncached docker build"
+            docker build \
+              --build-arg BASE_IMAGE=catthehacker/ubuntu:act-latest \
+              --build-arg LLVM_VERSION=22 \
+              --build-arg MESON_VERSION=latest \
+              --tag "$REGISTRY_IMAGE:latest" \
+              --file Dockerfile \
+              .
+            docker push "$REGISTRY_IMAGE:latest"
+          fi