diff --git a/cartographer/common/lockless_queue.h b/cartographer/common/lockless_queue.h
index 2517439..17c7ea0 100644
--- a/cartographer/common/lockless_queue.h
+++ b/cartographer/common/lockless_queue.h
@@ -64,7 +64,7 @@ class LocklessQueue {
       data_list_head_ = data_list_head_->next;
       std::unique_ptr<T> data = std::move(node->data);
       PushNodeToList(&free_list_head_, node);
-      return std::move(data);
+      return data;
     }
     return nullptr;
   }
diff --git a/cartographer/mapping/3d/hybrid_grid_test.cc b/cartographer/mapping/3d/hybrid_grid_test.cc
index 62309de..333b114 100644
--- a/cartographer/mapping/3d/hybrid_grid_test.cc
+++ b/cartographer/mapping/3d/hybrid_grid_test.cc
@@ -212,11 +212,15 @@ struct EigenComparator {
 TEST_F(RandomHybridGridTest, FromProto) {
   const HybridGrid constructed_grid(hybrid_grid_.ToProto());
 
-  std::map<Eigen::Vector3i, float, EigenComparator> member_map(
-      hybrid_grid_.begin(), hybrid_grid_.end());
+  std::map<Eigen::Vector3i, float, EigenComparator> member_map;
+  for (const auto& cell : hybrid_grid_) {
+    member_map.insert(cell);
+  }
 
-  std::map<Eigen::Vector3i, float, EigenComparator> constructed_map(
-      constructed_grid.begin(), constructed_grid.end());
+  std::map<Eigen::Vector3i, float, EigenComparator> constructed_map;
+  for (const auto& cell : constructed_grid) {
+    constructed_map.insert(cell);
+  }
 
   EXPECT_EQ(member_map, constructed_map);
 }
diff --git a/cmake/modules/FindAbseil.cmake b/cmake/modules/FindAbseil.cmake
index 80d35c5..14cd42b 100644
--- a/cmake/modules/FindAbseil.cmake
+++ b/cmake/modules/FindAbseil.cmake
@@ -52,7 +52,6 @@ if(NOT TARGET standalone_absl)
     "${ABSEIL_PROJECT_BUILD_DIR}/absl/meta/${prefix}absl_meta${suffix}"
     "${ABSEIL_PROJECT_BUILD_DIR}/absl/numeric/${prefix}absl_int128${suffix}"
     "${ABSEIL_PROJECT_BUILD_DIR}/absl/numeric/${prefix}absl_numeric${suffix}"
-    "${ABSEIL_PROJECT_BUILD_DIR}/absl/synchronization/${prefix}absl_synchronization${suffix}"
     "${ABSEIL_PROJECT_BUILD_DIR}/absl/types/${prefix}absl_any${suffix}"
     "${ABSEIL_PROJECT_BUILD_DIR}/absl/types/${prefix}absl_bad_any_cast${suffix}"
     "${ABSEIL_PROJECT_BUILD_DIR}/absl/types/${prefix}absl_bad_optional_access${suffix}"