A git subcommand to recursively archive a repo containing
submodules. The git clones of the bare repos are cached
in --git-base (default: $HOME/.git-archiver/repos)

$ cd my-repo && git-archive HEAD > out.tar
$ git-archive --git-dir=my-repo master > master.tar
$ git-archive --git-dir=my-repo develop:sub/dir > subdir.tar
$ git-archive --git-dir=my-repo --skip-fix | tar xi -C /path/to/extract
$ git-archive --git-dir=my-repo | gzip | tar zx -C /path/to/extract