Martin von Zweigbergk <martinvonz@google.com> [Fri, 16 Oct 2020 15:05:43 -0700] rev 45807
fix: suggest --source instead of --rev on empty revset
`--source` is the recommended flag for regular users (`--rev` is
available for advanced users).
Differential Revision: https://phab.mercurial-scm.org/D9224