$ git submodule update --init
Cloning into '/home/erik/go/src/nacl/vendor/golang.org/x/crypto'...
fatal: '/home/erik/git/github.com/golang/crypto.git' does not appear to be a git repository
fatal: Could not read from remote repository.

Please make sure you have the correct access rights
and the repository exists.
fatal: clone of 'file:///home/erik/git/github.com/golang/crypto.git' into submodule path '/home/erik/go/src/nacl/vendor/golang.org/x/crypto' failed
Failed to clone 'vendor/golang.org/x/crypto'. Retry scheduled
Cloning into '/home/erik/go/src/nacl/vendor/golang.org/x/crypto'...
fatal: '/home/erik/git/github.com/golang/crypto.git' does not appear to be a git repository
fatal: Could not read from remote repository.

Please make sure you have the correct access rights
and the repository exists.
fatal: clone of 'file:///home/erik/git/github.com/golang/crypto.git' into submodule path '/home/erik/go/src/nacl/vendor/golang.org/x/crypto' failed
Failed to clone 'vendor/golang.org/x/crypto' a second time, aborting