AC_ARG_WITH(libpcre1,
AS_HELP_STRING([--with-libpcre1],[support Perl-compatible regexes via libpcre1 (default is NO)])
AS_HELP_STRING([], [ARG can be also prefix for libpcre library and headers]),
+ if test -n "$USE_LIBPCRE1"; then
+ AC_MSG_ERROR([Only supply one of --with-libpcre or its synonym --with-libpcre1!])
+ fi
+
if test "$withval" = "no"; then
USE_LIBPCRE1=
elif test "$withval" = "yes"; then