             std_variants.append(os.path.join(dn, 'db0'))             std_variants.append(os.path.join(dn, 'db0'))             for x in gen_db_minor_ver_nums(0):                 std_variants.append(os.path.join(dn, "db0%d"%x))                 std_variants.append(os.path.join(dn, "db0.%d"%x))             for x in gen_db_minor_ver_nums(0):                 std_variants.append(os.path.join(dn, "db0%d"%x))                 std_variants.append(os.path.join(dn, "db0.%d"%x))          