Package Upgrades in FOSS Distributions: Details and Challenges ∗

The upgrade problems faced by Free and Open Source Soft-ware distributions have characteristics not easily found else-where. We describe the structure of packages and their role in the upgrade process. We show that state of the art package managers have shortcomings inhibiting their ability to cope with frequent upgrade failures. We survey current counter-measures to such failures, argue that they are not satisfactory, and sketch alternative solutions