I would continue to use out-of-date. Since you last used OpenBSD, there have been some enhancements that may be of interest:
You will find pkg_delete(8) now has "-a" option to delete any unneeded build dependencies :
Code:
-a Delete unused dependencies (packages that are not needed
by anything tagged as installed manually). Can be used
without pkgnames. If used with pkgnames, it will only
delete non manual installs in the list.
The distributed ports builder, dpb(1), has been around as a semi-private tool for some years but has now reached the maturity point where it has been discussed publicly on misc@ and has its own snall section in the FAQ (
15.3.9). I mention it because it can use a more simply edited pathlist from your out-of-date run to complete your ports building. You will find the executable in /usr/ports/infrastructure/bin, and its man page in /usr/ports/infrastructure/man. The mandoc(1) program can be used with the latter and your favorite $PAGER.