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/jlayton/linux.git/commit/?id=f9306e1825450ef6983cf1ae3cf03cfe115424ba
        git remote add jlayton https://git.kernel.org/pub/scm/linux/kernel/git/jlayton/linux.git
        git fetch --no-tags jlayton deleg-ace
        git checkout f9306e1825450ef6983cf1ae3cf03cfe115424ba
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang-18 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=x86_64 olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang-18 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=x86_64 SHELL=/bin/bash fs/nfsd/