Previously Martijn Faassen wrote:
People have been saying that since Linux distributions use external indexes, we should too, as we are dealing with the same problem as Linux distributions. While the problem is similar, I think the nature of development makes our problems, and therefore our solutions, quite different from the way distributions do it.
How are we different?
We have many, many different small distributions (package + dependencies) that can be combined. We have such a small distribution for each application. We have such a small distribution for each extension. Not just that. We have such a small distribution for each *release* of an application. We have such a small distribution for each *release* of an extension.
I therefore still believe that version dependency information should move out of external indexes and into packages.
Unless I'm missing something that is exactly what Linux distributions are doing. Each package has its own list of dependencies and conflicts (just as important). When a package is uploaded to a distribution archive that information is copied out of the package and included in the distribution index. That is important since it allows you to grab the index and calculate the whole dependency graph without having to download packages. You can know in advance if something is installable without having to download dozens of pacakges and only then discovering that it will never work. Linux package managers can also handle multiple distributions. If you look at apt for example it can handle as many distributions as you want. You can set priorities for them at distribution-scale (ie always prefer packages from distribution X), at release scale (ie always prefer packages from release Y even if release Z has a newer version) or package scale (package A has to come from distribution X). This is extremely common. If you install a Debian or Ubunutu machine you will always use two distributions: the one for the release, which will never change, and one with security fixes for just that release. Often you will also configure distributions with specific backports (needed because Debian releases are far apart) or for specific products (for your Enlightement 17 snapshot for example which Debian does not have). The terminolpgy is slightly different (archive versus index, package versus egg, depends versus requires, enlightenment versus grok, etc.) but the problem is still the same. Wichert. -- Wichert Akkerman <wichert@wiggy.net> It is simple to make things. http://www.wiggy.net/ It is hard to make things simple.