reproduce (this is a W=1 build):
        # https://github.com/jimc/linux/commit/81602811f92edaa27e63714ea280ed3077621caa
        git remote add jimc https://github.com/jimc/linux.git
        git fetch --no-tags jimc dd-shrink-6a5
        git checkout 81602811f92edaa27e63714ea280ed3077621caa

        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=$HOME/0day COMPILER=gcc-10.5.0 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=nios2 olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-10.5.0 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=nios2 SHELL=/bin/bash lib/