reproduce (this is a W=1 build):
        git clone https://github.com/intel/lkp-tests.git ~/lkp-tests
        # https://github.com/isilence/linux/commit/e483c8c11f7f015f2d540fcf6335b69f736938f3
        git remote add isilence https://github.com/isilence/linux
        git fetch --no-tags isilence dmabuf-rw-v1-test
        git checkout e483c8c11f7f015f2d540fcf6335b69f736938f3
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang-20 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=x86_64 olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang-20 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=x86_64 SHELL=/bin/bash