> One small caveat, building the man pages requires Ronn[2], which is a Ruby gem 
> not available in Guix. Roundup will build without Ronn as well, it will just 
> be missing the man pages. Is this acceptable?

If possible, try to package Ronn and build the man pages. If not,
perhaps leave a TODO comment.

> What module would be best suited for a command-line testing framework?

(gnu packages check) is probably the right module for a testing framework.