build-sys: enable all system extensions

This directive ensures stuff like large file support works without anyone
even noticing.

Reference: https://www.gnu.org/software/autoconf/manual/autoconf-2.64/html_node/Posix-Variants.html

diff --git a/configure.ac b/configure.ac
index 11fece610ef3d09d33702a8e0fc82caff14ea2bf..bc87c865c5f241ddcca4d1c0e19585acb3c19758 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -5,6 +5,7 @@ AC_INIT([mtr],
   [http://www.BitWizard.nl/mtr/])
 AC_CONFIG_SRCDIR([mtr.c])
 AC_CONFIG_AUX_DIR([build-aux])
+AC_USE_SYSTEM_EXTENSIONS
 AM_INIT_AUTOMAKE([
   1.7.9
   foreign