feat: do not start building image if tag.pacakge not present

build.sh

@@ -5,4 +5,8 @@ set -e
 TAG=${1:-latest}
 REGISTRY=${2:-theia}
 
-docker build --build-arg "version=$TAG" . -t "$REGISTRY:$TAG" --no-cache
+if test -f "$TAG.package.json"; then
\ No newline at end of file
+    docker build --build-arg "version=$TAG" . -t "$REGISTRY:$TAG" --no-cache
+else
+    echo "$TAG.package.json: file does not exist"
+fi
\ No newline at end of file