Replaces, Conflicts and Provides (was Re: Upgrade procedure for tetex)
>>>>> "Chris" == Chris Fearnley <email@example.com> writes:
Chris> 'Chow Chi-Ming wrote:'
>>>>>>> "Chris" == Chris Fearnley <firstname.lastname@example.org> writes:
Chris> I think most of the old tex packages can be automatically
Chris> uninstalled with a variation on this. But the tetex-base
Chris> and/or -bin need to Provides the old packages so things don't
Chris> blow up in process.
>> I am confused. What are these ``things'' and how will they ``blow
>> up''? The package mentioned in the Provides field are virtual
>> package names. Do we have an alternative (La)TeX system in Debian
>> so that we need virtual packages?
Chris> "Blow up" is my way of saying dselect will complain loudly.
Chris> One can use Provides to give dpkg assurances that the upgrade
Chris> will work. Conceptually this use of Provides differs from
Chris> virtual packages. The idea is that the new tetex packages
Chris> should provide the old TeX packages so dpkg will allow the old
Chris> tex packages to be replaced.
We really need some help from dpkg/dselect experts here. From my
programmer's manual (188.8.131.52) the purpose of Provides: is to give
virtual package names. And I am under the impression that a package
will be replace/removed _without_ it being provided by some other
For example, the package fileutils Replaces and Conflicts color-ls but
there is no color-ls package anymore and no other package Provides
color-ls. This doesn't stop the old color-ls package being replaced
_completely_ by fileutils. I tought this is the way to obsolete a
tetex packages are using exactly the same mechanism but dpkg doesn't
seem to be able to remove multiple old packages.
Billy C.-M. Chow <email@example.com>
Department of Systems Engineering
The Chinese University of Hong Kong