Fix RAFT_LOG_TRACE_VEC after the rapids-logger migration

cpp/include/raft/core/logger.hpp

@@ -56,12 +56,12 @@ inline rapids_logger::logger& default_logger()
 }  // namespace RAFT_EXPORT raft
 
 #if (RAFT_LOG_ACTIVE_LEVEL <= RAPIDS_LOGGER_LOG_LEVEL_TRACE)
-#define RAFT_LOG_TRACE_VEC(ptr, len)                                             \
-  do {                                                                           \
-    std::stringstream ss;                                                        \
-    ss << raft::detail::format("%s:%d ", __FILE__, __LINE__);                    \
-    print_vector(#ptr, ptr, len, ss);                                            \
-    raft::default_logger().log(RAPIDS_LOGGER_LOG_LEVEL_TRACE, ss.str().c_str()); \
+#define RAFT_LOG_TRACE_VEC(ptr, len)                                        \
+  do {                                                                      \
+    std::stringstream ss;                                                   \
+    ss << __FILE__ << ":" << __LINE__ << " ";                               \
+    raft::print_vector(#ptr, ptr, len, ss);                                 \
+    raft::default_logger().log(rapids_logger::level_enum::trace, ss.str()); \
   } while (0)
 #else
 #define RAFT_LOG_TRACE_VEC(ptr, len) void(0)

cpp/tests/CMakeLists.txt

@@ -101,6 +101,7 @@ if(BUILD_TESTS)
     core/operators_host.cpp
     core/handle.cpp
     core/interruptible.cu
+    core/logger.cu
     core/nvtx.cpp
     core/mdarray.cu
     core/mdbuffer.cu

cpp/tests/core/logger.cu

@@ -0,0 +1,54 @@
+/*
+ * SPDX-FileCopyrightText: Copyright (c) 2026, NVIDIA CORPORATION.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+/*
+ * RAFT_LOG_TRACE_VEC expands to void(0) unless RAFT_LOG_ACTIVE_LEVEL is TRACE,
+ * so a build at the default logging level never compiles its body. Raise the
+ * level for this translation unit only, so the macro is actually instantiated.
+ */
+#include <rapids_logger/logger.hpp>
+
+#undef RAFT_LOG_ACTIVE_LEVEL
+#define RAFT_LOG_ACTIVE_LEVEL RAPIDS_LOGGER_LOG_LEVEL_TRACE
+
+#include <raft/core/logger.hpp>
+#include <raft/core/resource/cuda_stream.hpp>
+#include <raft/core/resources.hpp>
+#include <raft/util/cudart_utils.hpp>
+
+#include <rmm/device_uvector.hpp>
+
+#include <gtest/gtest.h>
+
+#include <vector>
+
+namespace raft {
+
+// Compiling these at all is the point: the macro previously referenced
+// raft::detail::format, which no longer exists, an unqualified print_vector,
+// and a log level constant where the enumerator is expected.
+
+TEST(Logger, TraceVecHostPointer)
+{
+  const std::vector<int> host_data{1, 2, 3, 4};
+  ASSERT_NO_THROW(RAFT_LOG_TRACE_VEC(host_data.data(), host_data.size()));
+}
+
+TEST(Logger, TraceVecDevicePointer)
+{
+  // print_vector inspects the pointer with cudaPointerGetAttributes and copies
+  // device memory back to the host, so cover that branch as well.
+  raft::resources handle;
+  auto stream = resource::get_cuda_stream(handle);
+
+  const std::vector<int> host_data{5, 6, 7, 8};
+  rmm::device_uvector<int> device_data(host_data.size(), stream);
+  raft::update_device(device_data.data(), host_data.data(), host_data.size(), stream);
+  resource::sync_stream(handle, stream);
+
+  ASSERT_NO_THROW(RAFT_LOG_TRACE_VEC(device_data.data(), device_data.size()));
+}
+
+}  // namespace raft