Fix was obtained from http://marc.info/?l=fedora-extras-commits&m=137852553509836&w=2 . Patch file can be obtained from https://bugzilla.redhat.com/attachment.cgi?id=794884&action=diff
Looks good to me. Please commit. Please also raise the issue upstream, if you haven't already.
A commit references this bug: Author: acm Date: Wed Mar 30 16:26:34 UTC 2016 New revision: 412173 URL: https://svnweb.freebsd.org/changeset/ports/412173 Log: - Fix issue with DESTDIR and stage-qa on some GNUStep apps. PR: 208402 Submitted by: me Approved by: maintainer Obtained from: http://marc.info/?l=fedora-extras-commits&m=137852553509836&w=2 Changes: head/devel/gnustep-make/Makefile head/devel/gnustep-make/files/ head/devel/gnustep-make/files/patch-Instance_framework.make