* Jeff Johnson <n3...@mac.com> [May 22. 2011 22:04]: > > I see no reason for anything _EXCEPT_ the usual PRCO Gang Of Four: > Provides: > Requires: > Conflicts: > Obsoletes: >
>From a pure RPM pov, I fully agree. However, from a user/packager pov, additional dependencies are useful. In SUSE (not only SLES10, but all versions of SUSE since SLES10) these are used to e.g. support the following use cases: 1. The VLC packager wants a 'best effort' experience for the VideoLan movie player by pulling in as many codecs as possible during install. However, VLC fails gracefully if a codec is not available, so all the codecs are not strictly required and VLC installation should not fail if a codec is missing. To achieve this behaviour in the VLC package, 'recommends' are used to pull-in codec package which are installable 2. When looking at a product at the Amazon website, users are pointed to other products with "customer who looked at this also looked at that". This is useful information, esp. when you have a huge amount of products and putting them all into one list is not practical. This is where 'suggests' is helpful. The packager can add 'hints' to the package, to point to other useful and interesting packages. 3. You found a new game package which might also interest your kids. However, there are only foreign translations available for this package and your kid doesn't understand a word. After a couple of weeks, your package update application shows a new translation package, you install it and your kid is finally happy. The translation package has a "supplements" dependency to the original game thereby enabling the package update application to detect and install it. There are many more uses, esp. when it comes to language and hardware support where SUSE makes use of weak dependencies to improve the user experience. Of course, the information encoded in weak dependencies could be stored differently or even in a different place. By putting it into the package, you get a clearly defined place, clear semantics, and packagers don't have to edit multiple places. Klaus --- SUSE LINUX Products GmbH, GF: Jeff Hawn, Jennifer Guild, Felix Imendörffer, HRB 16746 (AG Nürnberg) Maxfeldstraße 5, 90409 Nürnberg, Germany ______________________________________________________________________ RPM Package Manager http://rpm5.org Developer Communication List rpm-devel@rpm5.org
