reproduce (this is a W=1 build):
        # https://github.com/jpirko/linux_mlxsw/commit/632e6dd46feb3a874a82d83535f9e3fd973231b3
        git remote add jpirko-mlxsw https://github.com/jpirko/linux_mlxsw
        git fetch --no-tags jpirko-mlxsw wip_attestation_pre_rfc_draft1
        git checkout 632e6dd46feb3a874a82d83535f9e3fd973231b3

        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