What happened in your environment?

$ oras tag root:test --oci-layout test1
Error: unable to add tag for 'root@test': invalid reference: missing registry or repository

What did you expect to happen?

Should tag test in folder root to test1

How can we reproduce it?

$ oras tag root@test --oci-layout test1

What is the version of your ORAS CLI?

oras v1.2.0-beta.1

What is your OS environment?

Ubuntu 20.04

Are you willing to submit PRs to fix it?

• Yes, I am willing to fix it.