[Yum] conflicts between explicit and implicit Requires: in a group of packages

[Michael Schroeder]

On Wed, Oct 09, 2019 at 03:29:35PM -0400, Brian J. Murrell wrote:
> I have a situation which I'm trying to understand the nature of and if
> there is any resolution.
> 
> Let's say I have two versions of a package named widgit in a repo,
> widgit-1.0.0 and widgit-1.3.0.  They both provide libwidgit.so.1().
> 
> Then let's say I have a package foo which Requires: widgit = 1.0.0 and
> also Requires: bar.  bar Requires libwidgit.so.1() and is also in the
> repo.
> 
> If I try to install foo, yum seems unable to reconcile that widgit-
> 1.0.0 satisfies both foo and bar and instead seems to want to try to
> install widgit-1.3.0, I assume to satisfy bar's Requires:
> libwidgit.so.1() (without consideration of foo's constraint) which of
> course conflicts with foo's Requires: widgit = 1.0.0.
> 
> I note that dnf seems smart enough to figure this all out though.  Is
> this just a limitation of yum that I am not going to be able to get
> past?

Yum normally doesn't backtrack, so it stops with an error if it runs
into a dependency problem. You can try the --skip-broken option to
enable some backtracking.

Dnf uses a SAT solver which always finds a solution (if one exists).

Cheers,
  Michael.

-- 
Michael Schroeder                                   mls at suse.de
SUSE LINUX GmbH,           GF Jeff Hawn, HRB 16746 AG Nuernberg
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