reproduce (this is a W=1 build):
        # https://git.kernel.org/pub/scm/linux/kernel/git/mark/linux.git/commit/?id=fe331f10804b0205503506bac2cd91599ff6163a
        git remote add mark https://git.kernel.org/pub/scm/linux/kernel/git/mark/linux.git
        git fetch --no-tags mark stacktrace/tests
        git checkout fe331f10804b0205503506bac2cd91599ff6163a

        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=$HOME/0day COMPILER=gcc-15.2.0 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=csky olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-15.2.0 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=csky SHELL=/bin/bash