Hi Masahiro,

FYI, the error/warning still remains.

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head:   7059c2c00a2196865c2139083cbef47cd18109b6
commit: cc8a51ca6f05ade72f7dd2624bc5f9b948e216fc kbuild: always create directories of targets
date:   4 months ago
config: powerpc-randconfig-r032-20201206 (attached as .config)
compiler: powerpc-linux-gcc (GCC) 9.3.0
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/torvalds/linux.git/commit/?id=cc8a51ca6f05ade72f7dd2624bc5f9b948e216fc
        git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
        git fetch --no-tags linus master
        git checkout cc8a51ca6f05ade72f7dd2624bc5f9b948e216fc
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=powerpc 

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

All errors (new ones prefixed by >>):

>> cc1: fatal error: opening output file arch/powerpc/boot/dts/fsl/.mpc8568mds.dtb.dts.tmp: No such file or directory
   compilation terminated.

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0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org