repo: rephrase the "missing requirement" error message Unknown requirements will now be reported as: abort: repository requires features unknown to this Mercurial: largefiles! (see http://mercurial.selenic.com/wiki/MissingRequirement for more information) Some features of this phrasing: * avoid double ':' in abort message * make it more clear who requires and knows what * don't quote the requirement names - it is not something the user entered or need the exact spelling of ... and it is "identifiers" that are unambiguous anyway * remove double hint by removing "(upgrade Mercurial)" comment * don't mention upgrading Mercurial without mentioning enabling the feature - instead, just refer to wiki page for both * don't just talk about "details", talk about "more information"