reproduce (this is a W=1 build):
        # https://github.com/ambarus/linux-0day/commit/8a167346a33aa28c6e422739e69abc87f57f81bc
        git remote add ambarus https://github.com/ambarus/linux-0day
        git fetch --no-tags ambarus syzkaller-id-5ecbc557fcdb8a2864e876f690ef377db999c50f
        git checkout 8a167346a33aa28c6e422739e69abc87f57f81bc
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        make W=1 O=build_dir ARCH=i386 olddefconfig
        make W=1 O=build_dir ARCH=i386 SHELL=/bin/bash