reproduce (this is a W=1 build):
        # https://github.com/cornelisnetworks/linux/commit/f09b053c0b35d3b9de750922b56cbf341eac7434
        git remote add cornelisnetworks https://github.com/cornelisnetworks/linux.git
        git fetch --no-tags cornelisnetworks for-upstream_20260402-1611
        git checkout f09b053c0b35d3b9de750922b56cbf341eac7434

        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 drivers/infiniband/hw/hfi2/