From 817371b225c70c49847b5c0932e0e98fa5bbd947 Mon Sep 17 00:00:00 2001
From: gabime <gmelman1@gmail.com>
Date: Fri, 18 Nov 2016 16:56:25 +0200
Subject: [PATCH] Fix issue #317 (Build error on raspberry pi)

---
 include/spdlog/details/os.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/spdlog/details/os.h b/include/spdlog/details/os.h
index 86efa0dc..763a4ad6 100644
--- a/include/spdlog/details/os.h
+++ b/include/spdlog/details/os.h
@@ -344,7 +344,7 @@ inline std::string errno_str(int err_num)
         return "Unkown error";
 
 #elif defined(__FreeBSD__) || defined(__APPLE__) || defined(ANDROID) || \
-      ((_POSIX_C_SOURCE >= 200112L) && ! _GNU_SOURCE) // posix version
+      ((_POSIX_C_SOURCE >= 200112L) && ! defined(_GNU_SOURCE)) // posix version
 
     if (strerror_r(err_num, buf, buf_size) == 0)
         return std::string(buf);