diff --git a/jvm-packages/pom.xml b/jvm-packages/pom.xml
index b57b569db926..3d4e8cdd73e9 100644
--- a/jvm-packages/pom.xml
+++ b/jvm-packages/pom.xml
@@ -72,6 +72,17 @@
                 <module>xgboost4j-spark</module>
                 <module>xgboost4j-flink</module>
             </modules>
+            <build>
+                <plugins>
+                    <plugin>
+                        <groupId>org.apache.maven.plugins</groupId>
+                        <artifactId>maven-surefire-plugin</artifactId>
+                        <configuration>
+                            <skipTests>true</skipTests>
+                        </configuration>
+                    </plugin>
+                </plugins>
+            </build>
         </profile>
 
         <profile>
diff --git a/jvm-packages/xgboost4j-spark/src/test/scala/ml/dmlc/xgboost4j/scala/spark/PerTest.scala b/jvm-packages/xgboost4j-spark/src/test/scala/ml/dmlc/xgboost4j/scala/spark/PerTest.scala
index 24bc00e1824e..ac9eba37a17d 100644
--- a/jvm-packages/xgboost4j-spark/src/test/scala/ml/dmlc/xgboost4j/scala/spark/PerTest.scala
+++ b/jvm-packages/xgboost4j-spark/src/test/scala/ml/dmlc/xgboost4j/scala/spark/PerTest.scala
@@ -59,7 +59,7 @@ trait PerTest extends BeforeAndAfterEach { self: AnyFunSuite =>
   private def getOrCreateSession = synchronized {
     if (currentSession == null) {
       currentSession = sparkSessionBuilder.getOrCreate()
-      currentSession.sparkContext.setLogLevel("ERROR")
+      currentSession.sparkContext.setLogLevel("INFO")
     }
     currentSession
   }
diff --git a/jvm-packages/xgboost4j-spark/src/test/scala/ml/dmlc/xgboost4j/scala/spark/XGBoostRegressorSuite.scala b/jvm-packages/xgboost4j-spark/src/test/scala/ml/dmlc/xgboost4j/scala/spark/XGBoostRegressorSuite.scala
index 1bdea7a827bd..3e241f5001be 100644
--- a/jvm-packages/xgboost4j-spark/src/test/scala/ml/dmlc/xgboost4j/scala/spark/XGBoostRegressorSuite.scala
+++ b/jvm-packages/xgboost4j-spark/src/test/scala/ml/dmlc/xgboost4j/scala/spark/XGBoostRegressorSuite.scala
@@ -132,6 +132,20 @@ class XGBoostRegressorSuite extends AnyFunSuite with PerTest with TmpFolderPerSu
     assert(testDF.count() === prediction.length)
   }
 
+  test("ranking: test position bias") {
+    val paramMap = Map("eta" -> "1", "max_depth" -> "6", "silent" -> "0", "verbosity" -> "3",
+      "objective" -> "rank:ndcg", "num_workers" -> numWorkers, "num_round" -> 5,
+      "group_col" -> "group", "tree_method" -> treeMethod, "lambdarank_unbiased" -> true, "eval_metric" -> "ndcg")
+
+    val trainingDF = buildDataFrameWithGroup(Ranking.train)
+    val testDF = buildDataFrame(Ranking.test)
+    val model = new XGBoostRegressor(paramMap).fit(trainingDF)
+
+    val prediction = model.transform(testDF).collect()
+    println("hello---------hongfei")
+    assert(testDF.count() === prediction.length)
+  }
+
   test("use weight") {
     val paramMap = Map("eta" -> "1", "max_depth" -> "6", "silent" -> "1",
       "objective" -> "reg:squarederror", "num_round" -> 5, "num_workers" -> numWorkers,
diff --git a/src/objective/lambdarank_obj.cc b/src/objective/lambdarank_obj.cc
index d0ff5bda5bde..bcc666409992 100644
--- a/src/objective/lambdarank_obj.cc
+++ b/src/objective/lambdarank_obj.cc
@@ -36,6 +36,7 @@
 #include "xgboost/span.h"                  // for Span, operator!=
 #include "xgboost/string_view.h"           // for operator<<, StringView
 #include "xgboost/task.h"                  // for ObjInfo
+#include "../collective/communicator-inl.h"  // for Allreduce, Broadcast, Finalize, GetProcessor...
 
 namespace xgboost::obj {
 namespace cpu_impl {
@@ -314,6 +315,8 @@ class LambdaRankObj : public FitIntercept {
       CHECK_EQ(info.weights_.Size(), n_groups) << error::GroupWeight();
     }
 
+    collective::Print("hongfeili-cpp lambdarank_unbiased: " + std::to_string(param_.lambdarank_unbiased));
+
     if (ti_plus_.Size() == 0 && param_.lambdarank_unbiased) {
       CHECK_EQ(iter, 0);
       ti_plus_ = linalg::Constant<double>(ctx_, 1.0, p_cache_->MaxPositionSize());