Broken sets in software repository evolution

Modern software systems are built by composing components drawn from large repositories, whose size and complexity increase at a fast pace. Software systems built with components from a release of a repository should be seamlessly upgradeable using components from the next release. Unfortunately, users are often confronted with sets of components that were installed together, but cannot be upgraded together to the latest version from the new repository. Identifying these broken sets can be of great help for a quality assurance team, that could examine and fix these issues well before they reach the end user. Building on previous work on component co-installability, we show that it is possible to find these broken sets for any two releases of a component repository, computing extremely efficiently a concise representation of these upgrade issues, together with informative graphical explanations. A tool implementing the algorithm presented in this paper is available as free software, and is able to process the evolution between two major releases of the Debian GNU/Linux distribution in just a few seconds. These results make it possible to integrate seamlessly this analysis in a repository development process.