try fix

Author: Alex-PLACET

test/CMakeLists.txt

@@ -235,12 +235,9 @@ file(GLOB XTENSOR_PREPROCESS_FILES files/cppy_source/*.cppy)
 include(${CMAKE_SOURCE_DIR}/cmake/sanitizers.cmake)
 
 if(USE_SANITIZER MATCHES "memory" AND CMAKE_CXX_COMPILER_ID MATCHES "Clang")
-  set(XTENSOR_MSAN_IGNORELIST_FILE "${CMAKE_CURRENT_SOURCE_DIR}/msan_ignorelist.txt")
-  set_source_files_properties(
-    main.cpp
-    PROPERTIES
-      COMPILE_OPTIONS "-fsanitize-ignorelist=${XTENSOR_MSAN_IGNORELIST_FILE}"
-  )
+  # doctest's String union triggers MSan false positives during
+  # static-init reporter registration. Fixed in main.cpp with
+  # __attribute__((no_sanitize("memory"))) on doctest functions.
 endif()
 
 # This target should only be run when the test source files have been changed.

test/main.cpp

@@ -1,5 +1,23 @@
+#ifdef __clang__
+#if __has_feature(memory_sanitizer)
+// Suppress MSan false positives in doctest's String union comparison.
+// doctest::String uses a union of stack/heap storage; the padding
+// between union members is flagged as uninitialized during strcmp
+// inside reporter registration at static-init time.
+// no_sanitize("memory") suppresses the check while still allowing
+// shadow memory propagation for stores.
+#pragma clang attribute push(__attribute__((no_sanitize("memory"))), apply_to = function)
+#endif
+#endif
+
 #define DOCTEST_CONFIG_IMPLEMENT_WITH_MAIN
 #if defined(XTENSOR_DISABLE_EXCEPTIONS)
 #define DOCTEST_CONFIG_NO_EXCEPTIONS_BUT_WITH_ALL_ASSERTS
 #endif
 #include "doctest/doctest.h"
+
+#ifdef __clang__
+#if __has_feature(memory_sanitizer)
+#pragma clang attribute pop
+#endif
+#endif