Consider tagging submodule "errors"?

[Rick-xuy]

I found that package github.com/rollbar/rollbar-go/errors is placed in submodule github.com/rollbar/rollbar-go/errors instead of root module.
However, it seems that submodule github.com/rollbar/rollbar-go/errors is not tagged. According to Go Modules wiki, submodule should be tagged like relative-path-to-root/vX.X.X. At now, when trying to import package github.com/rollbar/rollbar-go/errors, downstream would depends on pseudo-version of module github.com/rollbar/rollbar-go/errors.

github.com/rollbar/rollbar-go/errors v0.0.0-20191126182519-4b2c800372e7

I think it is not very readable and difficult to upgrade. This is not conductive to version control either. So, I propose whether it is possible to tag submodule properly. For example, errors/v0.0.1, errors/v1.4.5etc, so that other project can use tag to import this module in go.mod.