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
        # https://git.kernel.org/pub/scm/linux/kernel/git/cip/linux-cip.git/commit/?id=c6737c17f3653372565b944cc90aecc8c6cf693d
        git remote add cip https://git.kernel.org/pub/scm/linux/kernel/git/cip/linux-cip.git
        git fetch --no-tags cip linux-5.10.y-cip-rt-rebase
        git checkout c6737c17f3653372565b944cc90aecc8c6cf693d
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang-19 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=riscv olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang-19 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=riscv SHELL=/bin/bash