Created attachment 195677 [details] gbsplay.diff Builds fine with Clang as is now.
Committed, thanks!
A commit references this bug: Author: ehaupt Date: Tue Jul 31 06:15:22 UTC 2018 New revision: 475969 URL: https://svnweb.freebsd.org/changeset/ports/475969 Log: Remove gcc dependency. PR: 230227 Submitted by: tobik Changes: head/audio/gbsplay/Makefile