Hi Masahiro, First bad commit (maybe != root cause): tree: https://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild.git testing-kconfig head: e0b2802c637b32a68e0a9f99fc4bb1102518bf79 commit: 24b17f5f009bd77f46c48645dfd03d430439bd43 [24/25] kbuild: do not quote string values in include/config/auto.conf config: x86_64-randconfig-a003-20211213 (https://download.01.org/0day-ci/archive/20211213/202112131617.gF1CreGQ-lk...) compiler: clang version 14.0.0 (https://github.com/llvm/llvm-project b6a2ddb6c8ac29412b1361810972e15221fa021c) reproduce (this is a W=1 build): wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross chmod +x ~/bin/make.cross # https://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild.gi... git remote add masahiroy-kbuild https://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild.git git fetch --no-tags masahiroy-kbuild testing-kconfig git checkout 24b17f5f009bd77f46c48645dfd03d430439bd43 # save the config file to linux build tree mkdir build_dir COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=x86_64 prepare If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; All errors (new ones prefixed by >>): make[1]: *** [Makefile:1151: include/generated/autoksyms.h] Error 2 make[1]: Target 'prepare' not remade because of errors. make: *** [Makefile:219: __sub-make] Error 2 make: Target 'prepare' not remade because of errors. --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org