repoview: issue a special message when filtering hidden changesets Hidden changesets are by far the most common error case and is the only one[1] that can reach the user. We move to a friendlier message with a hint about how to access the data anyway. We should probably point to a help topic instead but we do not have such a topic yet. Example of the new output abort: hidden revision '4'! (use --hidden to access hidden revisions) [1] Actually, filtering from "served" can also reach the user during certain exchange operations.