$OpenBSD: patch-Source_cmTimestamp_cxx,v 1.1 2020/12/30 07:17:34 rsadowski Exp $

Index: Source/cmTimestamp.cxx
--- Source/cmTimestamp.cxx.orig
+++ Source/cmTimestamp.cxx
@@ -1,11 +1,11 @@
 /* Distributed under the OSI-approved BSD 3-Clause License.  See accompanying
    file Copyright.txt or https://cmake.org/licensing for details.  */
 
-#if !defined(_WIN32) && !defined(__sun)
+#if !defined(_WIN32) && !defined(__sun)  && !defined(__OpenBSD__)
 // POSIX APIs are needed
 #  define _POSIX_C_SOURCE 200809L
 #endif
-#if defined(__OpenBSD__) || defined(__FreeBSD__) || defined(__NetBSD__) ||    \
+#if defined(__FreeBSD__) || defined(__NetBSD__) ||    \
   defined(__QNX__)
 // For isascii
 #  define _XOPEN_SOURCE 700
