reproduce (this is a W=1 build):
        git remote add awilliam-vfio https://github.com/awilliam/linux-vfio.git
        git fetch awilliam-vfio for-linus
        git checkout awilliam-vfio/for-linus
        b4 shazam https://lore.kernel.org/r/20251204151003.171039-5-peterx@redhat.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=$HOME/0day COMPILER=clang-20 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=i386 olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang-20 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=i386 SHELL=/bin/bash drivers/vfio/pci/