Hi @dduffy,
No, currently the API (REST or Python) does not return the ID of the conflicting record that violates the uniqueness constraint. I can definitely see how that would be useful, and I’d recommend submitting it as an idea to our product team.
For the time being, you can do a try/catch for this sort of error in your creation call. If it occurs, you can then perform a quick find using the Version name you just tried to create to get this info and report it back to the script/log/user.