ReindexCommand calls dfs(M.Artifact, graph). When we ran reindex -p allura --solr, the first time it had this output: http://pastie.org/1836837 in which several classes were skipped. The second time: http://pastie.org/1839190 in which classes were repeated.
The repeated classes are allura.model.discuss.Post and forgediscussion.model.forum.ForumPost.
Next ming push may fix this.
This is still a problem with latest ming.