Index: configure
===================================================================
--- configure	(revision a254fa566143f6cb0e0b21fd04fa574bca33042a)
+++ configure	(revision c886f4bfea0c0fb9cc84145c2f0dbbb2ba16b6ab)
@@ -2557,4 +2557,5 @@
 # don't use the default CFLAGS as they unconditonnaly add -O2
 : ${CFLAGS=""}
+: ${CXXFLAGS=""}
 
 am__api_version='1.15'
Index: configure.ac
===================================================================
--- configure.ac	(revision a254fa566143f6cb0e0b21fd04fa574bca33042a)
+++ configure.ac	(revision c886f4bfea0c0fb9cc84145c2f0dbbb2ba16b6ab)
@@ -14,4 +14,5 @@
 # don't use the default CFLAGS as they unconditonnaly add -O2
 : ${CFLAGS=""}
+: ${CXXFLAGS=""}
 
 AM_INIT_AUTOMAKE([subdir-objects])