From: Enrico Tassi <gareuselesinge@debian.org>
Date: Sun, 30 Jun 2013 11:42:21 +0200
Subject: Fix build on hurd-i386

See http://www.debian.org/ports/hurd/
---
 ext/posix/posix.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/ext/posix/posix.c b/ext/posix/posix.c
index d07648c..a4b1268 100644
--- a/ext/posix/posix.c
+++ b/ext/posix/posix.c
@@ -11,6 +11,9 @@
 * With contributions by Roberto Ierusalimschy.
 * With documentation from Steve Donovan 2012
 */
+#ifdef __GNU__
+#define _GNU_SOURCE
+#endif
 
 #include <config.h>
 
@@ -692,6 +695,8 @@ static int Pgetcwd(lua_State *L)
 	}
 #else
 	long size = pathconf(".", _PC_PATH_MAX);
+	if (size == -1)
+		return pusherror(L, "pathconf");
 	void *ud;
 	lua_Alloc lalloc = lua_getallocf(L, &ud);
 	char *b, *ret;