The OpenBSD ports tree is maintained via CVS. Options:
- Maintain your own local copy of the -stable ports tree.
$ cvs -q up -Pd will update the tree and report any changes. You can do this manually, or add it to your /etc/daily.local script. See the cvs(1) and daily(8) man pages, and the AnonCVS link at the Project website.
- The ports-changes@ mailing list will post Changelog entries as they are committed. Any commits to 6.2-stable ports will be tagged OPENBSD_6_2.
- The CVS Changelog file is posted to most mirrors daily[1]. However this is all commits to all repositories. Any commits to 6.2-stable are tagged OPENBSD_6_2.
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[1]The Changelog update is currently broken at this time, it stopped on 16-Nov-2017. I only know this because the problem was reported to the bugs@ mailing list.