Created attachment 166421 [details] connect.2.diff This is straight from OpenBSD's connect(2). FreeBSD's version does not explain what namelen is and leaves you guessing.
A commit references this bug: Author: jgh Date: Thu Feb 4 18:03:06 UTC 2016 New revision: 295272 URL: https://svnweb.freebsd.org/changeset/base/295272 Log: - connect(2) Clarify namelen PR: 206838 Submitted by: t@tobik.me Approved by: bcr (mentor) MFH: after 1 week Differential Revision: https://reviews.freebsd.org/D5194 Changes: head/lib/libc/sys/connect.2
Thanks for the report!