Doing Quality Assurance work on Debian, a Linux distribution with more than 12000 packages, requires an impressive amount of computing power, which is usually not available for its developers. In this article, we report on the development of an infrastructure to run quality-assurance tasks on Debian using the Grid'5000 experimental platform. In particular, we focus on the problem of rebuilding all packages in Debian from source. We describe the details of this task, and the infrastructure we developed, with scalability and robustness in mind. The results we obtained are then presented, and we discuss possible improvements and lessons we learnt in the process, which might be useful in the context of other large-scale experiments.