reproduce (this is a W=1 build):
        git checkout db0d48554fbadd40a4b6e5e3fbbeae94ff546e53
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        make W=1 O=build_dir ARCH=x86_64 olddefconfig
        make W=1 O=build_dir ARCH=x86_64 SHELL=/bin/bash drivers/staging/