Fixup

Author: tgross35

Diff for: ci/run-docker.sh

@@ -48,14 +48,16 @@ run() {
       build_args=(
         "--cache-from" "type=local,src=/tmp/.buildx-cache"
         "--cache-to" "type=local,dest=/tmp/.buildx-cache-new"
-        "${build_args[@]:-}"
+        # This is the beautiful bash syntax for expanding an array but neither
+        # raising an error nor returning an empty string if the array is empty.
+        "${build_args[@]:+"${build_args[@]}"}"
         "--load"
       )
     fi
 
     docker "${build_cmd[@]:-build}" \
            -t "builtins-$target" \
-           ${build_args[@]:-} \
+           "${build_args[@]:-}" \
            "ci/docker/$target"
     docker run \
            --rm \