$NetBSD: patch-sigscheme_configure.ac,v 1.3 2021/04/03 05:13:07 ryoon Exp $

Correct _XOPEN_SOURCE.

--- sigscheme/configure.ac.orig	2020-08-24 21:28:26.000000000 +0000
+++ sigscheme/configure.ac
@@ -227,7 +227,7 @@ AC_CHECK_FUNCS(memalign)
 AC_CHECK_FUNCS(strdup,
   [
     # Overrides _POSIX_C_SOURCE
-    AC_DEFINE(_XOPEN_SOURCE, 500)
+    AC_DEFINE(_XOPEN_SOURCE, 600)
   ])
 AH_VERBATIM(_XOPEN_SOURCE,
 [/* Define to 500 to enable strdup(3). */