reproduce (this is a W=1 build):
        # https://github.com/alexshi/linux/commit/7c4dfaf03d4105a4daf3dc7baa6070bcab92a7fb
        git remote add alexshi https://github.com/alexshi/linux.git
        git fetch --no-tags alexshi pmdunify
        git checkout 7c4dfaf03d4105a4daf3dc7baa6070bcab92a7fb

        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 prepare