[Test-Announce] Fedora 18 Beta Test Compose 8 (TC8) Available Now!

Kevin Kofler kevin.kofler at chello.at
Sun Nov 11 17:34:11 UTC 2012


Adam Williamson wrote:
> The other classic case is that when a dependency of a package in the
> set of packages to be included in an image is satisfied by more than one
> other package, pungi pulls *all* the satisfying packages into the
> compose, not just one. This seems odd at first glance but not at second
> thought: it's possible for yum to make a guess at which one should be
> pulled in on a specific system - I think the rule it uses is 'causes the
> least amount of extra other dependencies' - but pungi can't do that,
> because it doesn't know what your eventual installed system is going to
> contain! If A requires foo, which is provided by GNOME-B and KDE-C, then
> pungi needs to include both on the DVD if it's including A, because on a
> GNOME install you'll probably wind up with the dependency fulfilled by
> GNOME-B, but on a KDE install you'll probably want to have it fulfilled
> by KDE-C. If we only pulled in GNOME-B to the DVD, a KDE install might
> look odd. (Just a theoretical example, but you get the point).

That nondeterministic behavior of yum really causes more harm than good. We 
can never be sure what's actually going to be installed when we Require 
something. And it doesn't properly solve the problem in your example because 
the heuristics sometimes do the wrong thing.

        Kevin Kofler



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