Created attachment 220489 [details] Log of build procedure Build of net/stone fails in amd64 sysytem. I remember there was no problem in i386 system. Because I do not have the knowledge on the programming language, I cannot make any patche.
A commit references this bug: Author: danfe Date: Wed Jan 13 11:18:29 UTC 2021 New revision: 561456 URL: https://svnweb.freebsd.org/changeset/ports/561456 Log: Unbreak the build against contemporary versions of OpenSSL. PR: 251783 Changes: head/net/stone/Makefile head/net/stone/files/patch-stone.c
It was because of OpenSSL, should be fixed in ports r561456.