fix by Elias Pipping

http://bugs.gentoo.org/240556
https://sourceforge.net/tracker/index.php?func=detail&aid=2155649&group_id=6389&atid=306389

--- configure
+++ configure
@@ -24160,7 +24160,7 @@
 	 test -z "$ac_c_werror_flag" ||
 	 test ! -s conftest.err
        } && test -s conftest.$ac_objext; then
-  ac_cv_cflags_no_writable_strings=`echo $ac_arg | -e 's,.*% *,,'` ; break
+  ac_cv_cflags_no_writable_strings=`echo $ac_arg | sed -e 's,.*% *,,'` ; break
 else
   echo "$as_me: failed program was:" >&5
 sed 's/^/| /' conftest.$ac_ext >&5