From dd9aeb60ae71d0f966ffce6cc1d36b4234c5466d Mon Sep 17 00:00:00 2001
From: Jiaming Yuan <jm.yuan@outlook.com>
Date: Tue, 19 May 2020 13:00:12 +0800
Subject: [PATCH] [JVM Packages] Catch dmlc error by ref. (#5678)

---
 jvm-packages/xgboost4j/src/native/xgboost4j.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/jvm-packages/xgboost4j/src/native/xgboost4j.cpp b/jvm-packages/xgboost4j/src/native/xgboost4j.cpp
index 636db2fb4..13529f6e1 100644
--- a/jvm-packages/xgboost4j/src/native/xgboost4j.cpp
+++ b/jvm-packages/xgboost4j/src/native/xgboost4j.cpp
@@ -151,7 +151,7 @@ XGB_EXTERN_C int XGBoost4jCallbackDataIterNext(
       global_jvm->DetachCurrentThread();
     }
     return ret_value;
-  } catch(dmlc::Error e) {
+  } catch(dmlc::Error const& e) {
     // only detach if it is a async call.
     if (jni_status == JNI_EDETACHED) {
       global_jvm->DetachCurrentThread();