reproduce (this is a W=1 build):
        # https://github.com/sean-jc/linux/commit/1b94e099a7fd1a1e2d61d908a51937b494816d7c
        git remote add sean-jc https://github.com/sean-jc/linux
        git fetch --no-tags sean-jc x86/gmem_inplace
        git checkout 1b94e099a7fd1a1e2d61d908a51937b494816d7c
        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=$HOME/0day COMPILER=clang-20 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=x86_64 olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang-20 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=x86_64 SHELL=/bin/bash