Another option: use git (if you use git 
)
You can specify git url and ref/tag (see git options), or use submodule with path option.
There is also Private packages in Hex (currently in beta), which has different pros & cons.
From my experience on using private repo for ruby gem… git way is much simpler since you can use git+ssh authentication like the main repo. There are some benefits of having private package repo for backup and audit purpose, but that usually applies only when you fetch all packages from the repo.
There is already a request to support hex on Artifactory - RTFACT-14011: Support for Erlang “hex” repos.
