This package still uses ruby 2.1. Ruby 2.1 is no longer supported upstream and will be removed soon. Please update your package to use a newer ruby slot. Use ruby 2.2 if you can only use one slot and your package is in arch Use ruby 2.3 if you can only use one slot and your package is in ~arch Use as many ruby targets as possible when you can use multiple slots.
This is done now. I took 2.2 and 2.3. Thanks!