--- libgo/misc/cgo/testcshared/src/libgo2/dup2.go.orig	2020-03-04 19:30:03.000000000 +1100
+++ libgo/misc/cgo/testcshared/src/libgo2/dup2.go	2020-09-09 22:08:04.775458000 +1000
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// +build darwin dragonfly freebsd linux,!arm64,!riscv64 netbsd openbsd
+// +build bsdsunix darwin dragonfly freebsd linux,!arm64,!riscv64 netbsd openbsd
 
 package main