I've just found work-in-progress port of opentracker, which you may wish to review. It was last edited 4 or 5 years ago, and the "TODO" file states it is not yet complete for three reasons, one of which is apparently a libowfat linking exception. This exception, possibly.
Gaining any value from the work-in-progress port will require detailed knowledge of OpenBSD's ports tree. An introduction to the ports tree can be found in the
Packages and Ports chapter of the OpenBSD FAQ. Much more information can be had from the key man pages ports(7) and bsd.port.mk(5), as well as in the ancillary man pages mentioned in the SEE ALSO sections of these two documents.
OpenBSD's work-in-progress ports collection is an unofficial "branch" of the tree, and may be found
here on Github. This individual port's files can be viewed from a browser
here.