Hello, please wrap your mails properly in future. APT development list CC'ed. kc.ubuntu.cz@centrum.cz wrote: > I would like to ask you a little bit controversal question. As a user I miss a package manager based on powerfull dependency solver. Using APT in DEB-based distributions, I can easilly create some kind of problem, APT is unable to solve. This is because the APT is the worst dependency solver almost ever invented. Proof can be found here: > > http://www.mancoosi.org/edos/manager.html Most tests from this page are just not practical. And they are didn't tested the aptitude's resolver, which is default for Debian now and has been proved to be more intelligent and coverable in the the most cases. > As a SUSE user, I'm used to work with Zypper/Libzypp package managementm using SAT solver. Since Opensuse 11.0, Libzypp is the best, fastest and te most powerfool tool to solve dependenies ever used in Linux distribution. Please, no much advertises here. SUSE goes its own way, and Debian has large own specific needs and particularities. > If you look at the comparison i posted above, you can se that APT is worse than Urpmi and SMART - which was the best dependency solver in that comparison. Zypper mentioned above, is a ittle bit better than smart: > If you look at users' feelings, situation will rotate significantly, due to my experience. > > I made some personal test, to compare the solver capabilities myself. I add KDE 4.2 repository to SUSE and Ubuntu, and made an upgrade from 4.1.3 to 4.2. After that i disabled KDE 4.2 repositories and delete one of the KDE 4.2 packages. This lead to inconsistent state, because KDE 4.2 repository was unavailable to repaire the dependency. The solution is obvious. Donwgrade somepackages back to KDE 4.1.3, to make dependencies OK because all 4.1.3 packages are available. > You might forgot that in the Debian way downgrade is unsupported at all, so APT treats the downgrade as one of worst possible solutions. > For APT (ubuntu), it was totaly imposible to find that existing solution. It gave it up because of broken dependencies. No parameters like "-f" worked. After that, I tried SMART, which solved the problem immediatelly. As I posted above, Smart has far better dependency solver. > > After that, I made the same situation using Zypper/Opensuse. It immediately found that existing solution as the fastest and with minimum changes, but offered me some other possibilities. > > So. APT is totally incapable to solve dependency problems and from mathematical point of view find only only obvious predictable solution. If it does not available, or package dependencies are written badly, it ends without solution. Mathematical point of view is something that does not value high in package management (at least, for me and some people). The package manager should have to deal with real problems on real distro in the first place, and APT is playing this role quite well (though can do it better, of course). > > Smart is far more better and Zypper is the best. In addition, both SMART and Zypper has ability to manage repositories and keys, which APT is unable. (you have to dit souces.list manualy) > > Is there any chance to implement better solvers to APT/Aptitude, chagne them to multiplatform and far better SMART or porting the best Zypper tool from Opensuse? APT team has a number of tasks to work. As usually, patches are usually welcome. I obviously think that "incapable and obsolete" (from subject of the letter) aren't the words which can characterize APT. With 'APT contributor' hat on, -- Eugene V. Lyubimkin aka JackYF, JID: jackyf.devel(maildog)gmail.com C++/Perl developer, Debian Maintainer
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