Add better error message for when nodes are missing in starterd

Change-Id: I0d02f8f81c18627dab3269418ebd81d78c3b6839
Signed-off-by: Austin Schuh <austin.linux@gmail.com>
diff --git a/aos/starter/starterd_lib.cc b/aos/starter/starterd_lib.cc
index 485d1f1..b8b7343 100644
--- a/aos/starter/starterd_lib.cc
+++ b/aos/starter/starterd_lib.cc
@@ -84,7 +84,8 @@
     if (aos::configuration::MultiNode(config_msg_)) {
       std::string_view current_node = event_loop_.node()->name()->string_view();
       for (const aos::Application *application : *applications) {
-        CHECK(application->has_nodes());
+        CHECK(application->has_nodes())
+            << ": Missing nodes on " << aos::FlatbufferToJson(application);
         for (const flatbuffers::String *node : *application->nodes()) {
           if (node->string_view() == current_node) {
             AddApplication(application);