Print cloud build logs when the task fails (#1989)

* Print cloud build logs when the task fails

* Add comment about why cloud build is made async

test/check-build-image-status.sh

@@ -37,6 +37,10 @@ if [ "$IMAGES_BUILDING" == true ]; then
           NEW_PENDING_BUILD_IDS+=( "$id" )
         ;;
         *)
+          echo "Fetching build log for build $id"
+          gcloud builds log "$id" || echo "Fetching build log failed"
+          # Intentionally placed this status echo at the end, because when a
+          # developer is looking at logs, sth at the end is most discoverable.
           echo "Cloud build with build id ${id} failed with status ${status}"
           exit 1
         ;;

test/presubmit-tests-with-pipeline-deployment.sh

@@ -79,6 +79,8 @@ echo "presubmit test starts"
 time source "${DIR}/test-prep.sh"
 echo "test env prepared"
 
+# We don't wait for image building here, because cluster can be deployed in
+# parallel so that we save a few minutes of test time.
 time source "${DIR}/build-images.sh"
 echo "KFP images cloudbuild jobs submitted"