Control: severity -1 wishlist Control: tags -1 + wontfix Control: close -1
Hi Yann, 2011-10-01 15:59 Yann Dirson:
Package: aptitude Version: 0.6.3-4 Severity: normal The "downgrade" use-case surely needs some love those days thanks to the moz foundation: I rapidly had a test of iceweasel 7 in unstable (eager to get better ram usage ;), just to conclude that so many extensions are not compatible. So let's try to get back to v6... iceweasel-dbg has a scrict dep, what are the first suggestions from aptitude ? Each of them summarized below, one per paragraph. I originally thought it was just a problem of "downgrade" being rated too bad - and incidentally, when asked to explicitely downgrade, aptitude should surely not inflict a downgrade-penalty to packages that are broken by the downgrade. But even then, how to explain that version from squeeze is elected first, then version from moz.d.n/wheezy, and that just downgrading -dbg to wheezy itself is not even ever considerered, whereas the priority of those packages is highest ?
From apt_preferences man page:
APT then applies the following rules, listed in order of precedence, to determine which version of a package to install. ยท Never downgrade unless the priority of an available version exceeds 1000. ("Downgrading" is installing a less recent version of a package in place of a more recent version. Note that none of APT's default priorities exceeds 1000; such high priorities can only be set in the preferences file. Note also that downgrading a package can be risky.) So even if pin priority is higher, since none of them is higher than 1000, it's not supposed to facilitate downgrades in any way. More in general, downgrades are not supported, so I don't think that it should be a goal of aptitude or any other tool making this action very easy / convenient / appear risk-free by working as seamlessly as new installs or upgrades.
[...] Remove the following packages: 1) iceweasel-dbg Keep the following packages at their current version: 1) iceweasel [7.0.1-1 (now, unstable)] Upgrade the following packages: 5) iceweasel [7.0.1-1 (now, unstable) -> 8.0~b1-1 (experimental)] Downgrade the following packages: 6) iceweasel [7.0.1-1 (now, unstable) -> 3.5.16-6 (stable)] [here after a number of combinations involving downgrade to 3.5, I had to reject that line manually] Downgrade the following packages: 5) iceweasel [7.0.1-1 (now, unstable) -> 3.6.23-1 (wheezy)] then the dreaded... open: 5318; closed: 48906; defer: 141; conflict: 187 No solution found within the allotted time. Try harder? [Y/n] open: 10316; closed: 72787; defer: 141; conflict: 187 No solution found within the allotted time. Try harder? [Y/n]
Perhaps you can try the interactive resolver, it is quite useful in any situation where the resolver gets stuck and one wants to guide the resolution to a quick end. In summary, sorry but I don't consider that it's worth spending time in an action that should happen rarely (if not avoided completely), when aptitude already provides other means to achieve the desired outcome. I am going to close the bug report, because after 4 years nobody was interested in implementing this or even seconding it, it doesn't make sense to keep it indefinitely gathering dust. Cheers. -- Manuel A. Fernandez Montecelo <manuel.montez...@gmail.com>