Since latest flightgear has builtin and recommended launcher, and fgrun is not maintained nor compatible with latest simgear, it should be removed. http://wiki.flightgear.org/FlightGear_Launch_Control#Status_03.2F2015
A commit references this bug: Author: marino Date: Fri Sep 30 13:54:13 UTC 2016 New revision: 422987 URL: https://svnweb.freebsd.org/changeset/ports/422987 Log: Remove obsolete ports games/fgrun The recommended launcher of the latest flightgear is inbuilt. fgrun is neither maintained nor compatible with it and thus is useless to everyone. PR: 213063 Submitted by: maintainer Changes: head/MOVED head/games/Makefile head/games/fgrun/
Done, thanks!