Re: Aptitude

[Paul E Condon <pecondon@peakpeak.com>]

On Sat, Nov 15, 2003 at 10:53:31PM +0000, K Lowe wrote:
> Dear Debian Users,
> 
> I installed Debian 3.0r0 from a CD set onto a reformatted hard disk (hdb) 
> which involved, among others, the following procedures:-
> (1) Did not chose tasksel.
> (2) Did not chose dselect.
> (3) Used apt-get to install aptitude.
> (4) Used aptitude to install xserver-s3.
> (5) Used aptitude to install x-window-system.
> (6) Used aptitude to install KDE. Therefore, I was able to de-select 60 
> out of 97 recommended dependency programs without creating a broken 
> package.
> (7) Used aptitude to install KDM.
> 
> Thus, I was able to successfully load a basic Linux operating system 
> which enabled me to run aptitude to install and remove programs in order 
> to determine their relevance for a proposed customised desktop.
> 
> Once the list of programs was finalised, and with a reformatted hard 
> disk, I undertook the above steps 1 to 7 again. However, repeating stage 
> 6 exactly, KDE always remained as a broken package (even if de-select 1 
> out of 97 recommended dependency programs), and therefore unable to 
> proceed.
> 
> Nevertheless, I decided to carry on and installed KDE, including all 
> recommended dependency programs, with the intention to remove unwanted 
> programs, e.g., KOffice, Kruler, etc., on completion of the above steps 1 
> to 7. To my surprise, this was not possible to achieve with aptitude or 
> Kpackage or synaptic, without removing KDE itself.
> 
> I shall be grateful if someone will kindly provide answers to these 
> questions:
> (1) Why is the KDE program a mega package, i.e., incorporate KOffice, 
> etc. programs?
> (2) Why did aptitude work the way I expected the first time, but not on 
> subsequent occasions?
> (3) Is there a program available to remove unwanted packages either 
> before or after installation?
> (4) Does the program deselect (very difficult to use) fulfil my 
> objectives (a minimalist installation)?
> 
> All assistance will be most appreciated.

KDE is a 'metapackage', it contains only dependency information that 
forces the installation of a selection of KDE real packages that the
maintainer and others have decided is a good starting selection of
KDE stuff. You can remove the KDE package without any of the KDE
functionality being lost, but if you remove any package that was
installed because the KDE package depends on it, the kde package
will also be removed because one of its dependencies is not satisfied.

The dependencies of a package are discovered by the maintainer during
the course of building and testing the package. In the case of
metapackages, the dependencies are purely a design decision of the
writer of the package. 

Why aptitude worked once but never again is hard to fathom. But you
have been mucking about in ways that the maintainers probably never
envisioned. If you are really determined, you can always repackage
stuff and put in you own (reduced) dependency lists. Some of your
packages might work.

HTH

-- 
Paul E Condon           
pecondon@peakpeak.com