check value of env var

Author: rithikanarayan

ci/input_files/build.yaml.tpl

@@ -53,6 +53,7 @@ build-layer ({{ $runtime.name }}-{{ $runtime.arch }}):
   variables:
     CI_ENABLE_CONTAINER_IMAGE_BUILDS: "true"
   script:
+    - echo $UPSTREAM_COMMIT_BRANCH
     - PYTHON_VERSION={{ $runtime.python_version }} ARCH={{ $runtime.arch }} ./scripts/build_layers.sh
 
 check-layer-size ({{ $runtime.name }}-{{ $runtime.arch }}):