Unclear error message when a repository has no tags

[lancep]

I'm trying to build a framework for https://github.com/jatoben/CommandLine Here's my Cartfile

github "jatoben/CommandLine"

I run carthage update and get the following output:

carthage update
*** Fetching CommandLine
No available version for github "jatoben/CommandLine" satisfies the requirement: 

It may be that CommandLine needs something in order for it to work with Carthage, but the lack of a descriptive error message from Carthage can be fixed.

[jspahrsummers]

I agree that the message here should be clearer. What it means is that the CommandLine repository lacks tags that can be used by Carthage.