reproduce (this is a W=1 build):
        git remote add axboe https://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux.git
        git fetch axboe for-next
        git checkout axboe/for-next
        b4 shazam https://lore.kernel.org/r/20260226192936.3190275-9-joshua.hahnjy@gmail.com

        # install powerpc64 cross compiling tool for clang build
        # apt-get install binutils-powerpc64-linux-gnu
        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=$HOME/0day COMPILER=clang-18 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=powerpc olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang-18 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=powerpc SHELL=/bin/bash mm/