reproduce (this is a W=1 build):
        git clone https://github.com/intel/lkp-tests.git ~/lkp-tests
        # https://git.kernel.org/pub/scm/linux/kernel/git/clk/linux.git/commit/?id=e1c20fc91c396384a8063063b32fce76c10dcdd8
        git remote add clk https://git.kernel.org/pub/scm/linux/kernel/git/clk/linux.git
        git fetch --no-tags clk clk-kunit
        git checkout e1c20fc91c396384a8063063b32fce76c10dcdd8
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang-18 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=i386 olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang-18 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=i386 SHELL=/bin/bash