reproduce (this is a W=1 build):
        # https://git.kernel.org/pub/scm/linux/kernel/git/cel/linux.git/commit/?id=1a33fc0e36a7ab0f77f8a72d3ba55b9ba5f1ad9b
        git remote add cel https://git.kernel.org/pub/scm/linux/kernel/git/cel/linux
        git fetch --no-tags cel nfsv3-xdrgen
        git checkout 1a33fc0e36a7ab0f77f8a72d3ba55b9ba5f1ad9b

        # install arm cross compiling tool for clang build
        # apt-get install binutils-arm-linux-gnueabi
        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=$HOME/0day COMPILER=clang-17 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=arm olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang-17 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=arm SHELL=/bin/bash fs/nfsd/