An unexpected quirk of the `<` specifier in a gemspec | Storm Consultancy - Your Digital Technology Agency

We updated the Gemfile to require the beta version: gem “rails”, “8.1.0.beta1” and ran bundle update rails. We had one dependency, bullet , that was incompatible. As this was a development tool and not used in the app we commented it out, ran the update again and everything went perfectly. We ran rails app:update, followed the steps in the upgrade guide, and our app was running on the pre-release version. A few weeks later, 8.1 was officially released. We immediately changed the Gemfile to require the final version: gem “rails”, “~> 8.1.0” and ran bundle update rails. Boom – loads of dependency mismatch errors. So what went wrong?.