reproduce (this is a W=1 build):
        git clone https://github.com/intel/lkp-tests.git ~/lkp-tests
        # https://github.com/isilence/linux/commit/40f3c0ed84549afda9f6b6f3b9503ee7191809a4
        git remote add isilence https://github.com/isilence/linux
        git fetch --no-tags isilence zcrx/v8-region-rebase
        git checkout 40f3c0ed84549afda9f6b6f3b9503ee7191809a4
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=hexagon olddefconfig
        ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=hexagon SHELL=/bin/bash