--- libev/configure.ac	2012/02/04 18:55:50	1.33
+++ libev/configure.ac	2012/02/04 19:09:29	1.34
@@ -1,3 +1,5 @@
+orig_CFLAGS="$CFLAGS"
+
 AC_INIT
 AC_CONFIG_SRCDIR([ev_epoll.c])
 
@@ -5,13 +7,18 @@
 AC_CONFIG_HEADERS([config.h])
 AM_MAINTAINER_MODE
 
-AC_PROG_INSTALL
-AC_PROG_LIBTOOL
+AC_PROG_CC
 
-if test "x$GCC" = xyes ; then
-  CFLAGS="-O3 $CFLAGS"
+dnl Supply default CFLAGS, if not specified
+if test -z "$orig_CFLAGS"; then
+  if test x$GCC = xyes; then
+    CFLAGS="-g -O3"
+  fi
 fi
 
+AC_PROG_INSTALL
+AC_PROG_LIBTOOL
+
 m4_include([libev.m4])
 
 AC_CONFIG_FILES([Makefile])