packages held back

[David Curtis]

On Thu, 17 Sep 2009 20:32:20 -0700 (MST)
Robert Holtzman <holtzm at cox.net> wrote:

> Just had to reinstall Hardy and ran the updates. The 2.6.24-19 kernel 
> packages were held back. This had never happened before when running 
> apt-get update and apt-get upgrade. Digging back in this list turned
> up "apt-get dist-upgrade" as a fix. My question is why didn't apt-get 
> upgrade pull in the dependencies?

Simply put, upgrade does not remove installed packages or introduce new
packages even if dependencies call for them. Packages requiring this
are, as you have noted, held back. Dist-upgrade will replace or bring
in packages that require these changes. Since the version number of
kernel packages are included in the name of the kernel package apt-get
treats them as new packages and does not upgrade (sneaky devs).  

Dist-upgrade over rides this policy using, according to 'man apt-get' a
"'smart' conflict resolution system", don't ask me how that works. It
will pull in new packages and remove conflicting ones to satisfy these
problematic dependencies. 

An interesting note; update-manager in Ubuntu goes even farther to
reconcile problem dependencies when moving from release to release,
hence the missive from Ubuntu that upgrading releases with a
sources.list edit and apt-get update && apt-get dist-upgrade is not a
supported method.

Dave