On Sun, Dec 25, 2016 at 10:47:00AM +0100, Olaf van der Spek wrote: > 2016-12-25 10:25 GMT+01:00 Julian Andres Klode <j...@debian.org>: > >> # apt dist-upgrade > >> The following packages will be REMOVED: > >> mariadb-server mariadb-server-10.0 mariadb-server-core-10.0 > >> 0 upgraded, 0 newly installed, 3 to remove and 0 not upgraded. > > > >> # apt install mariadb-server > >> 1 upgraded, 7 newly installed, 4 to remove and 0 not upgraded. > > > > This one removes a package more (and in addition to that also does > > other changes), so it really is worse solution than just removing > > mariadb-server altogether. > > That's not true right? > I think we agree the proper solution being to upgrade mariadb from 10.0 to > 10.1. > Only removing packages is (I think always) worse then a no-op.
Removing 3 is strictly better than removing 4 packages through, so the solution suggested by 'install' isn't better from an upgrade perspective – its just better from a "I want that package installed, do whatever you must" point of view. The most sensible decision in the scenario would indeed be doing nothing, which apt kinda tries to perform (you can kinda tell by observing "0 not upgraded" even through the client stack would be, so apt has performed a candidate version reset…). The removes linger there from previous decisions which it doesn't perform in the end as they conflicted with others. I guess we could teach the problem resolver to look at each remove after it is done to figure out if it is still needed much like the autoremover tries to deal with no longer needed NEW packages. I do think this specific instance is a rather temporary instance through as mariadb was only recently repeatedly uploaded, so two versions are still "fighting" over their spot in the archive. In so far the /var/lib/dpkg/status file of the situation before the dist-upgrade would be interesting – you might still have it in /var/backups – as these solver things tend to be highly dependent on mirror state and the specific packages installed on a machine. > Can't it detect mariadb-server-10.1 being a proper upgrade of > mariadb-server-10.0 and hence scoring this as neutral or positive? In general no, because that isn't a positive upgrade: It involves the removal of packages, which means features and services are removed other programs (packaged or not) might use and/or the user does. The very way this "upgrade" is packaged (= in another package forcibly removing the old) indicates that this upgrade isn't free: Something will have to adapt to changes – and changes are bad. Everyone hates changes: Ask all users of $DESKTOP_ENVIRONMENT being upgraded to $DEKTOP_ENVORNMENT+1. (The last bit is a bit exaggerated of course). It is what it is: A few new packages and a few packages removed – that you identify that as an upgrade is based on your knowledge of mariadb and how it (incompatibly!) changes in each new version: For apt it looks like the package 'default-texteditor' changed its depends from 'vim' to 'emacs' [actually worse than that as those two are co-installable] and that isn't an upgrade! ;) Best regards David Kalnischkies
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