reproduce (this is a W=1 build):
        # https://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux.git/commit/?id=a06776565b9e73512e880a95b66c198ae8e7e24a
        git remote add riscv https://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux.git
        git fetch --no-tags riscv for-next
        git checkout a06776565b9e73512e880a95b66c198ae8e7e24a

        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=$HOME/0day COMPILER=gcc-15.2.0 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=riscv olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-15.2.0 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=riscv SHELL=/bin/bash arch/riscv/kernel/