Gemini suggestion

Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com>

Author: kabir

tests/server-common/src/test/java/io/a2a/server/apps/common/AgentExecutorProducer.java

@@ -160,9 +160,9 @@ private void handleAgentToAgentTest(RequestContext context, AgentEmitter agentEm
                     } else {
                         handleLocally(userInput, agentEmitter);
                     }
-                } catch (Exception e) {
-                    agentEmitter.fail(new InternalError("Agent-to-agent test failed: " + e.getMessage()));
-                }
+} catch (Exception e) {
+    agentEmitter.fail(new InternalError("Agent-to-agent test failed: " + e.getMessage(), e));
+}
             }
 
             /**