static int option_verbosity;
static int option_progress = -1;
static enum transport_family family;
-static struct string_list option_config;
-static struct string_list option_reference;
+static struct string_list option_config = STRING_LIST_INIT_NODUP;
+static struct string_list option_reference = STRING_LIST_INIT_NODUP;
static int option_dissociate;
static int max_jobs = -1;