User Guide

@mrflip That *does*. It's called a Pessimistic Version Constraint. It forbids a MAJOR V upgrade and is A Good Thing™

5.3 Pessimistic Version Constraint If your project is using the Rational Versioning Policy to assign version numbers, then your users can take advantage of that fact to carefully specify exactly what versions of your software should work with their system. For example, suppose you have the following releases … Version 2.1.0 — Baseline Version 2.2.0 — Introduced some new (backward compatible) features. Version 2.2.1 — Removed some bugs Version 2.2.2 — Streamlined your code Version 2.3.0 — More new features (but still backwards compatible). Version 3.0.0 — Reworked the interface. Code written to verion 2.x might not work. Your clients have validated that version 2.2.0 works with their software, but version 2.1.0 doesn’t have a feature they need). Their require line would look like this … gem 'library', '>= 2.2.0' This is called an OptimisticVersionConstraint. They are optimi...

Full article: http://docs.rubygems.org/read/chapter/16