[Mageia-discuss] Package management system

[Richard]

On Tuesday 28 September 2010 22:21:08 Michael Scherer wrote:
> Le mardi 28 septembre 2010 à 20:20 +0100, Richard a écrit :
> > How much better could it possibly do this? What am I missing? You have
> > both mentioned alternatives, some of which I know by name, but in what
> > way do apt, yum or smart do this job any better?
>
> Well, apt is likely to be faster, c++ may be the cause.
>

That makes sudden sense; I had forgotten how slow rpmdrake has become while it 
builds and rebuilds its view of the installed packages inventory. I am 
guessing this is a "compiled-v-interpreted" thing. No matter how much faster 
is the PC I use, rpmdrake always seems to be slower than I would like/expect. 
That, of course, is where urpmi is most certainly your friend being many many 
times faster to get going - provided I already know the name of what I want 
to install.

> Smart is portable across type of repository. It also use a cleaner
> design or algorithm, according to his developer. Among nice features, it
> can draw graphs of the dependency, feature a command line shell or
> parallel downloads ( http://labix.org/smart/features )
>
A dependency graph would be pretty to look at, but it would be even better if 
the dependencies were to be colour coded to indicate which are true 
dependencies and which are just the packager's whim, and then give you the 
opportunity to ignore those which are neither wanted nor needed.
>
> ...Now, the "install package", "remove package" are basic features that all
> of them do. And I think that all packages managers are equal on that
> regard.
>
That was my feeling about package managers too so thank you for adding weight 
to the opinion.
>
> > I realise that package managers are needed because humans have to add
> > some intelligence in the form of what libraries are needed to get a
> > program to run. I also know that sometimes humans get this badly wrong
> > (try removing a library that you know will never be used and ask yourself
> > why rpmdrake wants to remove over 200 packages with it!). Do other
> > package managers manage to avoid this embarassing and frustrating
> > behaviour? or is it that it is just easier to get it right with package
> > types other than rpm?
>
> Nope, the problem is not linked to rpm or deb. If a library is needed,
> it is needed, that's simple.
>
> A system like emerge or macports ( macports is also in contribs, afaik )
> may however reduce the required dependency, depending on the software.
>
I sense a tendency in your response to the same confusion I am suffering from. 
On the one hand I find it easy to imagine that the packager is in total 
control of what a package regards as a "dependency" but on the other hand I 
must accept that your comment on macports may also be true. I do not know yet 
how to reconcile these apparent contradictions and I am really hoping I don't 
have to become the master of package management on all conceivable platforms 
before I can understand enough of this to make sense of it. 

I can fully grasp the concept that the structure of a package (rpm or deb) is 
not relevant to the program's requirement for one or more libraries, but I do 
not understand by what mechanism "nice to haves" are included as "must 
haves". Is it likely to be simply a packager's oversight or perhaps do some 
package types not enable the distinction to be made? If the latter, and rpms 
are of this type, then is ther a package type which does support the 
distinction?

Richard