reproduce (this is a W=1 build):
        # https://github.com/zen-kernel/zen-kernel/commit/6f7fb20c8e0c1938dcfda6adfa0f2080909db456
        git remote add zen https://github.com/zen-kernel/zen-kernel
        git fetch --no-tags zen 7.1/prjc
        git checkout 6f7fb20c8e0c1938dcfda6adfa0f2080909db456

        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=$HOME/0day COMPILER=gcc-11.5.0 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=nios2 olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.5.0 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=nios2 SHELL=/bin/bash kernel/sched/