I noticed that FedoraWorkspaceReader#findArtifact ignores an artifact's classifier (if any) when performing resolution. I've seen one case where (in an rpm build) the specfile performed a maven build, installing multiple artifacts distinguishable by 'classifier' into the reactor cache. A second build was then performed which resolved both artifacts to the same jar. I think the build succeeded anyways so this isn't as urgent.
Classifiers and stereotypes are currently not supported by XMvn, but their support is planned in the next major release of XMvn.
Fixed in xmvn-1.0.0-2
I believe that this bug is fixed in xmvn-1.0.0-2, which is available in Fedora Rawhide, so I am closing this bug now. The build containing the fix can be found at Koji: http://koji.fedoraproject.org/koji/buildinfo?buildID=463528