Mancoosi Weblog

During the question time of my FOSDEM 2010 talk about cross-distro dependency resolution, several people, mostly interested sysadms, asked me how they could contribute upgrade scenarios to the Mancoosi project. The idea is simple: we are working on improving dependency resolution techniques, algorithms, and tools; to that end we need a corpus of upgrade scenarios where shortcomings of state of the art tools are evident. We already have quite some of such upgrade (partly provided by members of the Mancoosi project, partly generated, etc.), but we could use more.

So, I'm hereby happy to announce the first public release of the mancoosi-contest package, for Debian-based distributions. mancoosi-contest essentially offers a wrapper, called dudf-save, that you can pre-pend to your usual invocations of package managers such as apt-get and aptitude. What it does is to capture all package meta-data that concerns your request, as well as the request itself, and the package manager output. All these data, which as you can imagine can be quite big, are collected in a DUDF document which is then bzipped and (optionally) uploaded to a DUDF collector service. All in all it is very similar to the popularity-contest architecture but instead of collecting installed packages is collecting specific upgrade attempts.

Of course participation is completely optional and the package is currently being provided unofficially by the Mancoosi project. Nevertheless, if you feel like having stumbled upon a challenging upgrade scenario, please consider contributing it using mancoosi-contest. We, for once, would be grateful :-) , and you will be helping out in improving the state of the art in dependency resolutions. Of course, the most interesting upgrade scenarios will also be considered as material for the forthcoming MISC competition, which we've discussed already on this blog.

Technically, dudf-save is still quite hackish and while apt-get support is OK, aptitude support is sub-optimal. In particular it will work properly only for "completely batch" aptitude sessions (or, better, it will not catch all intermediate solver scenarios that aptitude goes through when interactively asking questions to the user).

You can get mancoosi-contenst from mancoosi.debian.net

After the first test runs of the solver competition, at that time still called the 'Mancoosi internal Solver Competition (MiSC)', and the lessons we learned from that experience, the first Mancoosi International Solver Competition (MISC) will take place during the summer of 2010. The results will be announced at the LoCoCo 2010 workshop which will take place on July 10 as part of the FLoC conference.

More about the competion can be learned from the MISC web page. This page is intended for readers who are not yet familiar with the Mancoosi project; those who know the project already might want to jump to the bottom of that page where they will find pointers to the technical details. Participants of the internal MiSC competition beware: there are some changes to the rules, in particular we made the 'trendy' track more difficult by taking into account Recommends, that is non-mandatory package dependencies. Other significant changes include taking into account time. However, the total time used by a participating solver is only taken into account when breaking ties between solvers that otherwise are ranked equal, and furthermore only to determine the winner.

Let the games begin :-)