Every now and then I come across some borked data on our Phabricator install. Usually, this is a reference to some PHID which no longer exists, although I also found that we had a large number of commits (`phabricator_repository.repository_commit`) which didn't belong to any Phabricator repository. Some examples are as follows:
Whilst most of the time, this sort of data is not harmful in any way, in many cases it bothers me to the extend that I write some custom PHP or SQL to find these things and then fix them (usually by deleting them). I imagine it would be difficult to catch everything, but I would see benefit in some kind of `./bin/cleanup` script that could //at least// list orphaned PHIDs and maybe (in some cases) delete them as well.