build/ci: handle split up listing (#21293)

build/ci.go

@@ -1098,6 +1098,8 @@ func doPurge(cmdline []string) {
 	if err != nil {
 		log.Fatal(err)
 	}
+	fmt.Printf("Found %d blobs\n", len(blobs))
+
 	// Iterate over the blobs, collect and sort all unstable builds
 	for i := 0; i < len(blobs); i++ {
 		if !strings.Contains(blobs[i].Name, "unstable") {
@@ -1119,6 +1121,7 @@ func doPurge(cmdline []string) {
 			break
 		}
 	}
+	fmt.Printf("Deleting %d blobs\n", len(blobs))
 	// Delete all marked as such and return
 	if err := build.AzureBlobstoreDelete(auth, blobs); err != nil {
 		log.Fatal(err)