https://github.com/NGSolve/netgen/pull/171

--- libsrc/core/utils.hpp	2023-12-23 05:42:55.000000000 +0800
+++ libsrc/core/utils.hpp	2024-01-03 23:58:56.000000000 +0800
@@ -11,7 +11,7 @@
 
 #include "ngcore_api.hpp"       // for NGCORE_API and CPU arch macros
 
-#if defined(__APPLE__) && defined(NETGEN_ARCH_ARM64)
+#if defined(__APPLE__) && !defined(NETGEN_ARCH_AMD64)
 #include <mach/mach_time.h>
 #endif
 
@@ -62,7 +62,7 @@
 
   inline TTimePoint GetTimeCounter() noexcept
   {
-#if defined(__APPLE__) && defined(NETGEN_ARCH_ARM64)
+#if defined(__APPLE__) && !defined(NETGEN_ARCH_AMD64)
     return mach_absolute_time();
 #elif defined(NETGEN_ARCH_AMD64)
     return __rdtsc();