static void option_export_pack_edges(const char *edges)
{
	if (pack_edges)
		fclose(pack_edges);
	pack_edges = fopen(edges, "a");
	if (!pack_edges)
		die_errno("Cannot open '%s'", edges);
}
static void option_export_pack_edges(const char *edges)
{
	if (pack_edges)
		fclose(pack_edges);
	pack_edges = fopen(edges, "a");
	if (!pack_edges)
		die_errno("Cannot open '%s'", edges);
}