Thanks, @epriestley. Just one question: I note that resources/celerity/map.php is in the repository, though it is auto-generated, and that changes to it seem to be incorporated with other changes (i.e. not separate commits from CI). Therefore, should I rebase this onto current master and run bin/celerity map before landing, or something like that?

There were a few intervening commits, which surely would be normal following a review process (?), but I note that arc land has merged my change into current master rather than rebasing it onto current master. As there don't appear to be merge changesets everywhere in the repository, this doesn't seem to be the norm. Did I do something wrong? I just ran arc land hidden-anchor-fix as instructed by 'Next Step' in the web UI. Should I have instead pushed the 'Land Revision' link in the UI, or rebased manually immediately prior to landing, or something else? Would be handy to know in case some of my other work gets accepted. :-)