Re: [tlug] Number Your Feathers (Re: Printer Not Responding)

["Stephen J. Turnbull" <stephen@example.com>]

>>>>> "Evan" == Evan Monroig <evan.monroig@example.com> writes:

    Evan> Actually I thought (and that has been my experience) that it
    Evan> is quite easy to revert changes with apt-get if anything
    Evan> goes wrong. Maybe that would not be the case if the change
    Evan> pulls packages up to libc?

For most apps, even system services like the printer daemon, the
dependencies (in both directions) are contained in a quite small
circle of closely related packages, and downgrade/upgrade fiddling via
apt-get will be easy and safe.

For system software, you shouldn't take the chance, unless you're
prepared to reinstall from scratch.  There are 6000 packages in
Debian, I'm sure Ubuntu provides the same order of magnitude.  While
the vast majority of dependencies are predictable (foo-dev depends on
foo), there are a fair number of weirdos.  If the dependency graph
cycles and has side constraints on versions, you can get badly wedged.

Apt's ability to resolve such cycles and conflicts is very good, but
any update (except for the distro-recommended upgrades) that touches
the basic system software such as libc, GNOME, or the package manager
itself, should be avoided unless you know why you need to take such a
risk.


-- 
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