reproduce (this is a W=1 build):
        git clone https://github.com/intel/lkp-tests.git ~/lkp-tests
        # https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=951cd3a0866d29cb9c01ebc1d9c17590e598226e
        git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
        git fetch --no-tags linus master
        git checkout 951cd3a0866d29cb9c01ebc1d9c17590e598226e
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang-20 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=hexagon olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang-20 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=hexagon SHELL=/bin/bash ./ drivers/android/ drivers/block/drbd/ drivers/dma/xilinx/ drivers/firmware/broadcom/ drivers/gpu/drm/ drivers/iio/adc/ drivers/md/bcache/ drivers/media/platform/ drivers/mtd/nand/raw/ drivers/staging/ drivers/tty/ drivers/usb/dwc2/ drivers/usb/renesas_usbhs/ drivers/virtio/ drivers/watchdog/ fs/ kernel/ net/ security/landlock/