reproduce (this is a W=1 build):
        git clone https://github.com/intel/lkp-tests.git ~/lkp-tests
        # install riscv cross compiling tool for clang build
        # apt-get install binutils-riscv64-linux-gnu
        git remote add perf-tools-next https://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools-next.git
        git fetch perf-tools-next perf-tools-next
        git checkout perf-tools-next/perf-tools-next
        b4 shazam https://lore.kernel.org/r/20241205103729.14798-15-luxu.kernel@bytedance.com
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang-20 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=riscv olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang-20 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=riscv prepare