It's decent, but the complication introduced from the possibility of different tags in different source files poses a problem. I'd rather have all my deps in one place.
Additionally, it completely breaks if you depend on a package which depends on a specific version of another package. You are stuck using that version or forking your dependency to update the dep.
Additionally, it completely breaks if you depend on a package which depends on a specific version of another package. You are stuck using that version or forking your dependency to update the dep.