reproduce (this is a W=1 build):
        git clone https://github.com/intel/lkp-tests.git ~/lkp-tests
        # install arm cross compiling tool for clang build
        # apt-get install binutils-arm-linux-gnueabi
        # https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=d5c70627a79455154f5f636096abe6fe57510605
        git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
        git fetch --no-tags linus master
        git checkout d5c70627a79455154f5f636096abe6fe57510605
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang-20 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=arm olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang-20 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=arm SHELL=/bin/bash ./ arch/arm/mach-omap2/ drivers/dma/ drivers/firmware/efi/libstub/ drivers/gpu/drm/scheduler/ drivers/i2c/busses/ drivers/iio/adc/ drivers/nfc/pn533/ drivers/soc/tegra/ drivers/virtio/ drivers/watchdog/ dtbs fs/fuse/ fs/gfs2/ kernel/ net/