Related PR from 2012: https://bugs.php.net/bug.php?id=61189 The port Makefile should require PHP 5.3 and fail on other versions.
This port is not maintained. If you can submit a patch, it will probably go through pretty quickly.
A commit references this bug: Author: marino Date: Mon Feb 23 10:33:48 UTC 2015 New revision: 379671 URL: https://svnweb.freebsd.org/changeset/ports/379671 Log: devel/pecl-runkit: Limit to PHP 5.3 better There was an attempt to limit this port to PHP 5.3 using DEFAULT_PHP_VER but this port doesn't work with PHP 5.4 or later so explicitly ignore those versions. PR: 195823 Submitted by: Allen Landsidel Changes: head/devel/pecl-runkit/Makefile