Hi Eckart, Thanks for the bug report. We will take a closer look at your particular case.
The way the objective function is defined in p2 is described here: http://www.cril.univ-artois.fr/spip/publications/lash2010.pdf The behavior you observe might be expectable. Suppose that you have package x version 1 and x version 2 Version 1 has no dependencies and version 2 has dependencies on y z u and v. Suppose we have a minimal penalty of 1 for installing a package (to avoid installing a non necessary package). In that case, if the penalty for installing an "old" package for x1 is 4 for instance, then the solver prefers to install x1 for a penalty of 4 instead of x2 for a penalty of 5 (1 for each x2, y,,z, u, v). Note that with a bigger penalty for old versions, we could still install x2. I will check in your bug report if this is really what happens in your case. Cheers, Daniel Le 20 juil. 2011 à 13:22, Langhuth, Eckart a écrit : > Hi, > > As requested I created a p2 bug for this issue > https://bugs.eclipse.org/bugs/show_bug.cgi?id=352560 > > Best regards, > Eckart > > From: [email protected] [mailto:[email protected]] On > Behalf Of Pascal Rapicault > Sent: Montag, 18. Juli 2011 18:52 > To: P2 developer discussions > Subject: Re: [p2-dev] Projector weight function > > For a new install (which is the case in a tycho build), the intent is for the > resolver to return the highest version available. > For addition on top of an install or update, the algorithm is a bit more > complex but should favour the highest version of the things being in the > transitive closure of what is being changed. > > Could you please open a bug > (https://bugs.eclipse.org/bugs/enter_bug.cgi?product=Equinox) with the > necessary IUs to recreate the problem. > > Thx > > On 2011-07-14, at 4:46 PM, Langhuth, Eckart wrote: > > > Hi, > > while investigating a problem resulting in bug > https://bugs.eclipse.org/bugs/show_bug.cgi?id=352081 > I stumbled over the behavior of > org.eclipse.equinox.internal.p2.director.Projector. > > Out of curiosity. Is there a description of the weight function used to > determine a solution? > In my example a feature includes a single plugin without a version > constraint. (0.0.0) > The search scope contains two version of the required plugin. > The solution provided by the projector contains the plugin with the smaller > version. > My assumption would have been to prefer a solution with latest plugin version. > The difference I see is that the higher version plugin defines more > dependencies. > Is it intended to prefer a small installation over a new one? > > Best regards, > Eckart > _______________________________________________ > p2-dev mailing list > [email protected] > https://dev.eclipse.org/mailman/listinfo/p2-dev > > _______________________________________________ > p2-dev mailing list > [email protected] > https://dev.eclipse.org/mailman/listinfo/p2-dev _______________________________________________ p2-dev mailing list [email protected] https://dev.eclipse.org/mailman/listinfo/p2-dev
