Re: sources.list: experimental
lsorense@csclub.uwaterloo.ca (Lennart Sorensen) writes:
> On Tue, Dec 02, 2008 at 06:35:59PM +0100, Hans-J. Ullrich wrote:
>> just a question:
>>
>> adding an experimental source to the sources list (just to install a special
>> application from this), will an "aptitude upgrade" or "apt-get upgrade"
>> overwrite ALL installed packages ?
>
> upgrade doesn't do anything involving adding or removing packages.
> dist-upgrade does, so really using anything other than dist-upgrade ever
> is just a mistake. upgrade really shouldn't even be an option. At
> least for apt-get. Perhaps aptitude behaves differently.
Actualy you are verry wrong there. Not in what it is supposed to do
but in what actually happens and why update is a good idea.
As you say will do things involving adding or removing packages.
Unfortunately it is not always too smart about that and result depend
on the order of updates. For example:
Package: foo
Version: 1.2-3
Depends: foo-simple (= 1.2-3) | foo-heavy (= 1.2-3)
Now imagine you have foo 1.2-1 and foo-heavy 1.2-1 installed then
dist-upgrade will want to update foo 1.2-3. That will have broken
dependencies (foo-heavy 1.2-3 is not installed yet) so to fullfill
them it will add foo-simple 1.2-3. Only later it hits foo-heavy 1.2-1
and will also update that to 1.2-3.
By first doing an upgrade you have 2 effects:
1) many examples like above do get solved by upgrade
2) the number of packages for dist-upgrade is greatly reduced
often resulting in a better solution, at least from my experience
MfG
Goswin
PS: aptitude can be even more spectacular wrong if the dependencies
are currently broken like often in sid. The non-GUI mode I find mostly
unbearable.
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