Re: awk: essential virtual package?

[Christian Schwarz <schwarz@monet.m.isar.de>]

On 18 Feb 1998, Manoj Srivastava wrote:

> Hi,
> 
> >>"Christian" == Christian Schwarz <schwarz@monet.m.isar.de> writes:
> 
> Christian> On 18 Feb 1998, James Troup wrote:
> 
> Christian> [extremly essential vs. essential]
> 
> Christian> I fully agree to what James said. So I think it would be
> Christian> good to check out all "Essential" packages in which
> Christian> category they fall.
> 
> 	Umm, are we sure that the weaker essential package really are
>  essential? Does anyone remember the reason why? Can we document the
>  reasons then?

I think we cannot be sure that essential packages are really essential.
AFAIK, tagging a package essential has to effects:

  1. dpkg will never remove the package (unless forced to do so)
  2. other packages don't have to declare a dependency because of #1
  3. other packages can use essential packages in the maintainer
     scripts (postinst, etc.)

(is #3 correct?)

> Christian> Note, that from the package system's view, there shouldn't
> Christian> be a difference between these two categories--it's the
> Christian> maintainers who need to know which one a package is--in
> Christian> order to set up Depends or Pre-Depends.
> 
> 	Why not demote the latter set of packages to required?	
> 
> Christian> There was a suggestion on debian-devel about creating and
> Christian> maintaining a list of essential packages that explains the
> Christian> reasons why a specific package is marked essential. This
> Christian> list should also contain information about whether a
> Christian> package is `extremly essential' or just `essential.'
> 
> Christian> What do you think?
> 
> 	Maybe "just essential" is a synonym for required?

But `required' won't guarantee that the package is always installed. (You
can remove required packages very easily.)

> 	Oh, I agree we should have such a list, seeing that I made the
>  proposal. ;-)

Yes, I think the next step in this discussion is to assemble a list of
essential packages. 

Here is a small demonstration of how useful Lintian's lab is :-)

schwarz@kandinsky:/var/spool/lintian/binary$ for i in *; do if [ -f
"$i/fields/essential" ]; then echo -n "$i: "; cat "$i/fields/essential";
fi; done | grep -v ': no'

base-files: yes
base-passwd: yes
bash: yes
bsdutils: yes
debianutils: yes
diff: yes
dpkg: yes
e2compr: yes
e2fsprogs: yes
fileutils: yes
findutils: yes
grep: yes
gzip: yes
hostname: yes
ldso: yes
login: yes
mount: yes
ncurses-base: yes
ncurses-bin: yes
perl-base: yes
procps: yes
sed: yes
shellutils: yes
sysvinit: yes
tar: yes
textutils: yes
update: yes
util-linux: yes
schwarz@kandinsky:/var/spool/lintian/binary$ 

Note, that this list only covers arch: i386 and my local mirror has
timestamp Thu Feb 12 23:00:01 UTC 1998 (but Essential: fields don't change
that often :)

It would be nice if someone could start commenting which packages have
which `essential level' and why they are `essential'.


Thanks,

Chris

--                  Christian Schwarz
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