On Sunday 03 July 2005 12:14, R. Clayton <[EMAIL PROTECTED]> (<[EMAIL PROTECTED]>) wrote:
> I feel like answering RTFM again, but you've been reasonable and polite. > Thank you for your courtesy. > > 'apt-get upgrade' is restricted (and therefore safer) in that: > > under no circumstances are currently installed packages removed, > > Neither the apt-get nor the aptitude man page make that distinction (which > is not to say it's wrong, just that you can't learn it by RingTFM). It's a direct quote from 'man apt-get'; it says that the action of 'upgrade' is restricted in that it will not "under [any] circumstances" install new packages or remove existing packages. Allowing a package manager to removing packages at its discretion is simply not as safe. I always verify the proposed action(s) of 'aptitude dist-upgrade' before permitting it to continue; on occasion, as a set of related packages makes its way into 'unstable', aptitude may want to remove some packages I use because their dependencies are not currently satisfied. In my experience, the situation is always resolved after some (unspecified) period of time -- I think the upgrade to KDE 3.3 took a matter of weeks. The point is that the result of using 'dist-upgrade' on 'unstable' blindly may be unsatisfactory to the user. This is what I meant when I said 'upgrade' is safer. > It may be that dist-upgrade smartly resolves conflicts by removing > currently installed packages, but the man page doesn't explicitly indicate > that. As you point out, the apt-get and aptitude man pages do not say this. However, it's easily verified that 'apt-get dist-upgrade' and 'aptitude dist-upgrade' may well remove existing packages and/or install new packages to resolve dependencies. By adding the "-s" (or "--simulate") switch, you may verify this without actually making any changes. > The aptitude man page doesn't, except for the synopsis, mention > dist-upgrade at all. It does not, but the behavior is easily verified. > As an aside, the apt-get and aptitude man pages describe different > behaviors for upgrade. For apt-get, upgrade has the non-removal behavior > described above. For aptitude, the upgrade behavior is "Installed > packages will not be removed unless they are unused". As I said, the behavior of 'apt-get' and 'aptitude', while similar, are not identical. > This is on a debian testing system, upgraded once a week. Perhaps, then, you'll take the time to verify that what I said is a correct description of the behavior of apt-get and aptitude. -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
