I wrote a patch for the extattr* API based on the linux specific code for extended attributes. The patch has meanwhile made it into upstream and has been released as part of 1.4.36. Please provide an option to enable --with-attr in configure or make it the default (it's not actually enabled until you explicitely do so in the config file).
Created attachment 161485 [details] attr patch
Thanks, I've tested tested that it builds and runs. Since the developers didn't set it on by default, I also left it off. The diff is attached.
A commit references this bug: Author: miwi Date: Sat Jan 16 08:17:58 UTC 2016 New revision: 406198 URL: https://svnweb.freebsd.org/changeset/ports/406198 Log: - Add support for extended attributes - While here pet portlint - Bump PORTREVISION PR: 203398 Submitted by: Moritz Wilhelmy Approved by: maintainer Changes: head/www/lighttpd/Makefile