Il builds and passes its tests; dependent ports such as findlib and utop work as well. I don't know why it has been disabled on this platform for 10 years, but whatever prevented it from building or working has been fixed.
Index: Makefile =================================================================== RCS file: /OpenBSD/ports/lang/ocaml/Makefile,v retrieving revision 1.71 diff -u -p -r1.71 Makefile --- Makefile 29 Mar 2016 11:27:00 -0000 1.71 +++ Makefile 11 Apr 2016 06:08:43 -0000 @@ -1,7 +1,5 @@ # $OpenBSD: Makefile,v 1.71 2016/03/29 11:27:00 naddy Exp $ -NOT_FOR_ARCHS= hppa - MULTI_PACKAGES = -graphics -main COMMENT-main = ML language with complete class-based objective system