The builder-3.2.2 ebuild should have slot 3.2 instead of 3.1 since an app (e.g., rails 4.0) might require it use the 3.1.X series of builder gems and this slot confuses emerge enough that it thinks the 3.2.X series will satisfy the gem dependency when it does not. Reproducible: Always Steps to Reproduce: 1. emerge >=dev-ruby/builder-3.1.0 2. run an app that requires the gem ~> builder-3.1.0 Actual Results: App complains that it cannot find a proper version of builder since it is looking for builder 3.1.X and emerge installed 3.2.2 instead Expected Results: Things should just work.
Thanks for reporting, this is now fixed.