FreeBSD ports problems

For some reason, the FreeBSD ports tree decided to eat itself. Parts of it (i.e. entire categories) just aren’t there (and I doubt very much they ever were), like ports-mgmt. And there is absolutely no documentation on how to rebuild/repair a screwed up Ports Collection. The only vaguely non-mainstream thing I did was run 6.2-STABLE. Methinks I’ve done something wrong in switching that over, so am now rebuilding and making worlds again. Much scrolling text, as my younger brother would observe.