Gems can already specify which version of Ruby they depend on: https://guides.rubygems.org/specification-reference/#required_ruby_version https://guides.rubygem

Gems can already specify which version of Ruby they depend on: https://guides.rubygems.org/specification-reference/#required_ruby_version https://guides.rubygems.org/specification-reference/#require.... In practice you may not fully depend on it because people often write too permissive ranges (i.e. >= 2.7) and there has been some breaking changes between minor versions of Ruby 2.x so even if people write "~> 2.7" it may still be broken.