mydumper hangs when run with option -r 1

When I testing this software I supress by hangs when I make backup some tests databases.

after run: mydumper-0.6.1/mydumper -v 3 -o $dir -u $user -p $pass -r 1
I got output:

** Message: Thread 4 dumping data for `mysql`.`time_zone_leap_second`
** Message: Thread 2 dumping data for `mysql`.`time_zone_name`
** Message: Empty table mysql.tables_priv
** Message: Thread 3 dumping data for `mysql`.`time_zone_transition`
** Message: Empty table mysql.time_zone_leap_second
** Message: Thread 4 dumping data for `mysql`.`time_zone_transition_type`
** Message: Empty table mysql.time_zone
** Message: Empty table mysql.time_zone_transition
** Message: Thread 1 dumping data for `mysql`.`user`
** Message: Thread 3 dumping data for `test1`.`developers`
** Message: Empty table mysql.time_zone_transition_type
** Message: Thread 4 dumping data for `test1`.`tab1`
** Message: Empty table mysql.time_zone_name
** Message: Thread 4 dumping schema for `mysql`.`columns_priv`
** Message: Thread 3 dumping schema for `mysql`.`db`
** Message: Thread 2 dumping schema for `mysql`.`event`
** Message: Thread 4 dumping schema for `mysql`.`func`
** Message: Thread 3 dumping schema for `mysql`.`help_category`
** Message: Thread 1 dumping schema for `mysql`.`help_keyword`
** Message: Thread 4 dumping schema for `mysql`.`help_relation`
** Message: Thread 3 dumping schema for `mysql`.`host`
** Message: Thread 2 dumping schema for `mysql`.`help_topic`
** Message: Thread 4 dumping schema for `mysql`.`ndb_binlog_index`
** Message: Thread 3 dumping schema for `mysql`.`plugin`
** Message: Thread 2 dumping schema for `mysql`.`proc`
** Message: Thread 4 dumping schema for `mysql`.`procs_priv`
** Message: Thread 3 dumping schema for `mysql`.`servers`
** Message: Thread 1 dumping schema for `mysql`.`tables_priv`
** Message: Thread 4 dumping schema for `mysql`.`time_zone`
** Message: Thread 3 dumping schema for `mysql`.`time_zone_name`
** Message: Thread 2 dumping schema for `mysql`.`time_zone_leap_second`
** Message: Thread 4 dumping schema for `mysql`.`time_zone_transition`
** Message: Thread 3 dumping schema for `mysql`.`time_zone_transition_type`
** Message: Thread 1 dumping schema for `mysql`.`user`
** Message: Thread 4 dumping schema for `test1`.`developers`
** Message: Thread 2 dumping schema for `test1`.`tab1`

and mydumper hangs.
backup databases looks done.

debian_version 6.0.9
mysql-server-5.1

BTW
in mydumper --help
 -r, --rows Try to split tables into chunks of this many rows. This option turns off --chunk-filesize

but
when run:

mydumper-0.6.1/mydumper -v 3 -o $dir -u $user -p $pass -r

i got:
option parsing failed: Missing argument for -r, try --help

so, this option should be explain somting like that:

-r X, --rows X Try to split tables into chunks of this many rows, when X ....