reproduce (this is a W=1 build):
        # https://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms.git/commit/?id=863b2c5b18c975f73dd3008fac1a97b9168687a3
        git remote add arm-platforms https://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms.git
        git fetch --no-tags arm-platforms kvm-arm64/vgic-last_lr_irq-fixes
        git checkout 863b2c5b18c975f73dd3008fac1a97b9168687a3

        # install powerpc cross compiling tool for clang build
        # apt-get install binutils-powerpc64-linux-gnu
        # clang-24 might not be officially released. Try a lower version if installation fails.
        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=$HOME/0day COMPILER=clang-24 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=powerpc olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang-24 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=powerpc prepare