reproduce (this is a W=1 build):
        git remote add sre-power-supply https://git.kernel.org/pub/scm/linux/kernel/git/sre/linux-power-supply.git
        git fetch sre-power-supply for-next
        git checkout sre-power-supply/for-next
        b4 shazam https://lore.kernel.org/r/5eab51e111b092329519dd2c200858a522780626.1761699952.git.cy_huang@richtek.com

        git clone https://github.com/intel/lkp-tests.git ~/lkp-tests
        # apt-get install sparse
        # sparse version: v0.6.4-71-g610d841d

        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.5.0 ~/lkp-tests/kbuild/make.cross W=1 C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__ -fmax-errors=unlimited -fmax-warnings=unlimited' O=build_dir ARCH=nios2 olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.5.0 ~/lkp-tests/kbuild/make.cross W=1 C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__ -fmax-errors=unlimited -fmax-warnings=unlimited' O=build_dir ARCH=nios2 SHELL=/bin/bash drivers/power/supply/