用docker export导出容器快照出现一下问题：

$ docker export -o clever_dewdney-expose.tar clever_dewdney

open .docker_temp_019486347: Access is denied.

$ docker export --help

Usage:  docker export [OPTIONS] CONTAINER

Export a container's filesystem as a tar archive

Options:

  -o, --output string   Write to a file, instead of STDOUT

输入格式有问题还是其他原因，谢谢