On Fri, Feb 10, 2017 at 2:33 PM, Justin Cappos <[email protected]> wrote:
> Yes, don't use a SAT solver. It requires all metadata from all packages > (~30MB uncompressed) and gives hard to predict results in some cases. > I doubt there exists an algorithm where this is not the case. Also the lack of fixed dependencies is a substantial problem for a SAT > solver. Overall, we think it makes more sense to use a simple backtracking > dependency resolution algorithm. > As soon as you want to deal with version ranges and ensure consistency of the installed packages, backtracking stops being simple rather quickly. I agree lack of fixed dependencies is an issue, but I doubt it is specific to a SAT solver. SAT solvers have been used successfully in many cases now: composer (php), dnf (Red Hat/Fedora), conda or our own packages manager at Enthought in python, 0install. I would certainly be interested in seeing a proper comparison with other algorithms. David > Sebastien Awwad (CCed) has been looking at a bunch of data around the > speed and other tradeoffs of the different algos. Sebastien: Sometime > next week, can you write it up in a way that is suitable for sharing? > > Justin > > On Fri, Feb 10, 2017 at 1:59 PM, Wes Turner <[email protected]> wrote: > >> From the discussion on https://github.com/pypa/pip/is >> sues/988#issuecomment-279033079: >> >> >> - https://github.com/ContinuumIO/pycosat (picosat) >> - https://github.com/ContinuumIO/pycosat/blob/master/pycosat.c (C) >> - https://github.com/ContinuumIO/pycosat/blob/master/picosat.c >> - https://github.com/ContinuumIO/pycosat/tree/master/examples >> - https://github.com/enthought/sat-solver (MiniSat) >> - https://github.com/enthought/sat-solver/tree/master/simplesa >> t/tests >> - https://github.com/enthought/sat-solver/blob/master/requirem >> ents.txt (PyYAML, enum34) >> >> >> Is there a better way than SAT? >> >> On Fri, Feb 10, 2017 at 12:20 PM, Pradyun Gedam <[email protected]> >> wrote: >> >>> Yay! Thank you so much for a prompt and positive response! I'm pretty >>> excited and looking forward to this. >>> >>> On Thu, Feb 9, 2017, 20:23 Donald Stufft <[email protected]> wrote: >>> >>> I’ve never done it before, but I’m happy to provide mentoring on this. >>> >>> On Feb 8, 2017, at 9:15 PM, Pradyun Gedam <[email protected]> wrote: >>> >>> Hello Everyone! >>> >>> Ralf Gommers suggested that I put this proposal here on this list, for >>> feedback and for seeing if anyone would be willing to mentor me. So, here >>> it is. >>> >>> ----- >>> >>> My name is Pradyun Gedam. I'm currently a first year student VIT >>> University in India. >>> >>> I would like to apply for GSoC 2017 under PSF. >>> >>> I currently have a project in mind - the "pip needs a dependency >>> resolver" issue [1]. I would like to take on this specific project but am >>> willing to do some other project as well. >>> >>> For some background, around mid 2016, I started contributing to pip. The >>> first issue I tackled was #59 [2] - a request for upgrade command and an >>> upgrade-all command that has been open for over 5.5 years. Over the months >>> following that, I've have had the opportunity to work with and understand >>> multiple parts of pip's codebase while working on this issue and a few >>> others. This search on GitHub issues [3] also provides a good summary of >>> what work I've done on pip. >>> >>> [2]: https://github.com/pypa/pip/issues/988 >>> [2]: https://github.com/pypa/pip/issues/59 >>> [3]: https://github.com/pypa/pip/issues?q=author%3Apradyunsg >>> >>> Eagerly-waiting-for-a-response-ly, >>> Pradyun Gedam >>> >>> _______________________________________________ >>> Distutils-SIG maillist - [email protected] >>> https://mail.python.org/mailman/listinfo/distutils-sig >>> >>> >>> >>> — >>> >>> Donald Stufft >>> >>> >>> _______________________________________________ >>> Distutils-SIG maillist - [email protected] >>> https://mail.python.org/mailman/listinfo/distutils-sig >>> >>> >> >> _______________________________________________ >> Distutils-SIG maillist - [email protected] >> https://mail.python.org/mailman/listinfo/distutils-sig >> >> > > _______________________________________________ > Distutils-SIG maillist - [email protected] > https://mail.python.org/mailman/listinfo/distutils-sig > >
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