reproduce (this is a W=1 build):
        git checkout bfd453acb5637b5df881cef4b21803344aa9e7ac
        b4 shazam https://lore.kernel.org/r/c49d28aade36c044f0533d03b564ff65e00d9e05.1768573690.git.bcodding@hammerspace.com

        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=$HOME/0day COMPILER=clang-20 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=x86_64 olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang-20 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=x86_64 SHELL=/bin/bash fs/nfsd/