[Date Prev][Date Next] [Thread Prev][Thread Next] [Date Index] [Thread Index]

Re: FAQ: Essential vs. Required

On Thu, Aug 07, 2003 at 11:38:26AM +0200, Santiago Vila wrote:
> On Thu, 7 Aug 2003, Osamu Aoki wrote:
> > On Sun, Aug 03, 2003 at 12:11:37PM +0200, Santiago Vila wrote:
> > > In some sense, "required and essential" is like a priority over
> > > "just required" (expect that you can have a package of extra priority
> > > having the essential flag if it conflicts and replaces an essential package).
> >
> > ??? extra priority with essential ???  I do not understand.
> Essential is a flag, not a priority (that's why I said that it was
> only *like* a priority). They are orthogonal things, but due to the rule
> saying packages which conflict with others of optional or higher priorities
> should be extra, essential packages are either required or extra.

OK...  I think I know this...

> Imagine an e2fsprogs-cvs package which conflicts and replaces the
> normal e2fsprogs package. It should be extra, but if you install
> e2fsprogs-cvs to replace e2fsprogs, you should still be unable to
> remove e2fsprogs-cvs unless you use dpkg's --force-remove-essential
> option. So, a package like e2fsprogs-cvs should still be essential: yes
> to prevent its removal the same way e2fsprogs does.

But we do not have e2fsprogs-cvs.  I was looking for actual examples of
this type of case.  If we really have this kind of case, it is bast to
make e2fsprogs not "essential" but let some essential package depends on
it.  If e2fsprogs-cvs prfovides and replaces e2fsprogs, thing must be
OK.  Am I wrong?  I checked all main sections in tyesting and unstable.

All essentials are main and required.

> > [...]
> > "Essential: yes" means that this package
> > +requires to specify an extra force option to the package management
> > +system such as <prgn>dpkg</prgn> when removing from the system.  For
> > +example, <package>libc6</package>, <package>mawk</package>, and
> > +<package>makedev</package> are "Priority: required" and "Section: base"
> > +but are not "Essential: yes".
> However, you still need a --force-depends to remove libc6, which is
> still "an extra force option", so the example is not very clear.
> I would choose here more examples like makedev instead of libc6 and mawk.

Hmm.... you have a point.  But that is because we have so many packages
installed.  If it is minimum install, is this so?

Reply to: