diff -ruN build.orig/libcxx/include/CMakeLists.txt build/libcxx/include/CMakeLists.txt
--- build.orig/libcxx/include/CMakeLists.txt	2024-08-05 10:40:33.000000000 +0200
+++ build/libcxx/include/CMakeLists.txt	2024-09-13 15:02:44.249710564 +0200
@@ -1074,11 +1074,13 @@
     PERMISSIONS OWNER_READ OWNER_WRITE GROUP_READ WORLD_READ
     COMPONENT cxx-headers)
 
+  if (FALSE)
   # Install the generated IWYU file to the generic include dir.
   install(FILES "${LIBCXX_GENERATED_INCLUDE_DIR}/libcxx.imp"
     DESTINATION "${LIBCXX_INSTALL_INCLUDE_DIR}"
     PERMISSIONS OWNER_READ OWNER_WRITE GROUP_READ WORLD_READ
     COMPONENT cxx-headers)
+  endif()
 
   if (NOT CMAKE_CONFIGURATION_TYPES)
     add_custom_target(install-cxx-headers
