reproduce (this is a W=1 build):
        # https://github.com/gourryinverse/linux/commit/4fd6f53383d678673b9fd4df224a53c9da119f17
        git remote add gourryinverse https://github.com/gourryinverse/linux
        git fetch --no-tags gourryinverse scratch/gourry/cxl/region_rework_v3
        git checkout 4fd6f53383d678673b9fd4df224a53c9da119f17

        git clone https://github.com/intel/lkp-tests.git ~/lkp-tests

        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang-20 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=i386 olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang-20 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=i386 SHELL=/bin/bash drivers/cxl/core/