Created attachment 174880 [details] patch to Makefile Somewhere deep in the build the -m32 flag is invoked which some archs don't like. Just mark BROKEN.
A commit references this bug: Author: sunpoet Date: Sun Nov 6 17:23:13 UTC 2016 New revision: 425572 URL: https://svnweb.freebsd.org/changeset/ports/425572 Log: - Mark BROKEN on tier-2 archs PR: 212769 Submitted by: linimon Changes: head/security/p5-Crypt-Curve25519/Makefile
Committed. Thanks!