On Monday 18 April 2005 03:21 am, Branden Robinson wrote: > Can I beg and plead for this bug to be fixed, pleeeeeease? :) > > I'd be happy to help write a patch, except for the fact that I don't > actually understand precisely what dist-upgrade does. I know only these > things: > > * It doesn't work exactly like apt-get dist-upgrade. > * It will hold back packages that aptitude upgrade does not. > > If you want to corner me in IRC some time and brain dump, I can try to come > up with a patch to the manpage. > > Let me know what I can do to help.
The main problem is that aptitude's dist-upgrade is not terribly well defined (neither is apt-get's dist-upgrade, if it comes to that). It basically means "try hard to upgrade stuff, even if you have to install new packages or remove packages", but the decisions about how to resolve dependency problems are made by apt's dependency resolver, which is fairly deep black magic. Basically what happens is that everything is marked for upgrade, and then apt is called in to fix any remaining problems. apt is told to avoid breaking holds and to preserve deletions. It looks like it doesn't give instructions to preserve currently-installed packages or to preserve upgrades, but neither does apt's dist-upgrade (there's probably a reason for that, but if I ever knew it I've forgotten it). It's actually somewhat obscure to me why they produce different results at all. So to sum up, the only way I can see to document it that doesn't get into hairy technical details is "dist-upgrade will try harder than upgrade to upgrade all installed packages, installing or removing packages as necessary". aptitude's dist-upgrade has the additional feature that you can specify extra package actions, like this: aptitude dist-upgrade pkg1+ pkg2- ... Daniel -- /------------------- Daniel Burrows <[EMAIL PROTECTED]> ------------------\ | "That we should wish to cast him down and have no one in his place | | is not a thought that occurs to his mind. That we should wish to | | destroy the Ring itself has not yet entered into his darkest dream." | | -- Gandalf Grayhame | \------------ Evil Overlord, Inc: http://www.eviloverlord.com --------------/
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