The "repo" argument allows to contain "ref" as "package_name@ref", "package_name#pull" or "package_name[branch]". The function detects that "repo" contains "ref" and separates into pure repo and ref. If "repo" contains "ref" and "ref" argument is specified, the values in "repo" take precedence.
separate_into_package_and_reference(packages, original_ref)