reproduce (this is a W=1 build):
        # https://github.com/riteshharjani/linux/commit/744ed18f924d7aeb1a92993e90971120f0b7d4d4
        git remote add riteshharjani https://github.com/riteshharjani/linux
        git fetch --no-tags riteshharjani feat-secret-memfd-rfc-v1-0day
        git checkout 744ed18f924d7aeb1a92993e90971120f0b7d4d4

        git clone https://github.com/intel/lkp-tests.git ~/lkp-tests
        # apt-get install llvm-dev

        # save the config file
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-14.2.0 ~/lkp-tests/kbuild/make.cross W=1 ARCH=powerpc olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-14.2.0 ~/lkp-tests/kbuild/make.cross W=1 ARCH=powerpc 
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-14.2.0 ~/lkp-tests/kbuild/make.cross W=1 headers_install
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-14.2.0 ~/lkp-tests/kbuild/make.cross W=1 -C tools/testing/selftests