reproduce (this is a W=1 build):
        # https://git.kernel.org/pub/scm/linux/kernel/git/chao/linux.git/commit/?id=819157dce25d2c894a6c24f04e418dc680477c2a
        git remote add chao https://git.kernel.org/pub/scm/linux/kernel/git/chao/linux.git
        git fetch --no-tags chao dev-test
        git checkout 819157dce25d2c894a6c24f04e418dc680477c2a

        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 fs/