check variable resolution

Author: donoghuc

.buildkite/pull_request_pipeline.yml

@@ -158,6 +158,7 @@ steps:
       QUALIFIED_VERSION="$(.buildkite/scripts/common/qualified-version.sh)"
       SHA="$(git rev-parse --short HEAD)"
       DOCKER_REPOSITORY=docker.elastic.co/logstash/logstash-observability-sre
+      echo $DOCKER_REPOSITORY:$QUALIFIED_VERSION-$SHA
       ./gradlew --stacktrace artifactDockerObservabilitySRE -PfedrampHighMode=true
       docker tag $DOCKER_REPOSITORY:$QUALIFIED_VERSION $DOCKER_REPOSITORY:$QUALIFIED_VERSION-$SHA
       docker push $DOCKER_REPOSITORY:$QUALIFIED_VERSION-$SHA