diff --git a/mediapipe/framework/calculator_graph.cc b/mediapipe/framework/calculator_graph.cc
index 2a2088c6..33ca41fb 100644
--- a/mediapipe/framework/calculator_graph.cc
+++ b/mediapipe/framework/calculator_graph.cc
@@ -840,9 +840,12 @@ absl::Status CalculatorGraph::PrepareForRun(
 
 absl::Status CalculatorGraph::WaitUntilIdle() {
   if (has_sources_) {
-    LOG(WARNING) << "WaitUntilIdle called on a graph with source nodes, which "
-                    "is not fully supported at the moment.";
+    LOG_FIRST_N(WARNING, 1)
+        << "WaitUntilIdle called on a graph with source nodes, which "
+           "is not fully supported at the moment. Source nodes: "
+        << ListSourceNodes();
   }
+
   MP_RETURN_IF_ERROR(scheduler_.WaitUntilIdle());
   VLOG(2) << "Scheduler idle.";
   absl::Status status = absl::OkStatus();
@@ -1372,6 +1375,16 @@ const OutputStreamManager* CalculatorGraph::FindOutputStreamManager(
               .get()[validated_graph_->OutputStreamIndex(name)];
 }
 
+std::string CalculatorGraph::ListSourceNodes() const {
+  std::vector<std::string> sources;
+  for (auto& node : nodes_) {
+    if (node->IsSource()) {
+      sources.push_back(node->DebugName());
+    }
+  }
+  return absl::StrJoin(sources, ", ");
+}
+
 namespace {
 void PrintTimingToInfo(const std::string& label, int64_t timer_value) {
   const int64_t total_seconds = timer_value / 1000000ll;
diff --git a/mediapipe/framework/calculator_graph.h b/mediapipe/framework/calculator_graph.h
index 748d2fb3..00c922a3 100644
--- a/mediapipe/framework/calculator_graph.h
+++ b/mediapipe/framework/calculator_graph.h
@@ -597,6 +597,9 @@ class CalculatorGraph {
   // status before taking any action.
   void UpdateThrottledNodes(InputStreamManager* stream, bool* stream_was_full);
 
+  // Returns a comma-separated list of source nodes.
+  std::string ListSourceNodes() const;
+
 #if !MEDIAPIPE_DISABLE_GPU
   // Owns the legacy GpuSharedData if we need to create one for backwards
   // compatibility.