Queued, thanks. > + let parents = self > + .graph > + .parents(current) > + .unwrap_or((NULL_REVISION, NULL_REVISION)); > + let p0 = parents.0; I've renamed it to `p1` since that's the convention of Mercurial codebase. Maybe it can be rewritten as `let (p1, p2) = parents` to get rid of confusing tuple indexing.