pt-duplicate-key-checker --key-types=k doesn't work

[root@poseidon extracted]# pt-duplicate-key-checker --version
pt-duplicate-key-checker 2.0.3

Try to use key checks instead of fk checks:
[root@poseidon extracted]# pt-duplicate-key-checker --key-types=k
Can't use an undefined value as a HASH reference at /usr/bin/pt-duplicate-key-checker line 3658.

From PTDEBUG:
# SchemaIterator:3360 27373 Getting next schema object from dbh DBI::db=HASH(0x18ae3070)
# MySQLDump:696 27373 /*!40101 SET @OLD_SQL_MODE := @@SQL_MODE, @@SQL_MODE := REPLACE(REPLACE(@@SQL_MODE, 'ANSI_QUOTES', ''), ',,', ','), @OLD_QUOTE := @@SQL_QUOTE_SHOW_CREATE, @@SQL_QUOTE_SHOW_CREATE := 1 */
# MySQLDump:684 27373 DBI::db=HASH(0x18ae3070) USE `mysql`
# MySQLDump:701 27373 SHOW CREATE TABLE `mysql`.`general_log`
# MySQLDump:711 27373 /*!40101 SET @@SQL_MODE := @OLD_SQL_MODE, @@SQL_QUOTE_SHOW_CREATE := @OLD_QUOTE */
# MySQLDump:715 27373 This table is a base table
# TableParser:409 27373 Storage engine: CSV
# TableParser:230 27373 Table cols: `event_time`, `user_host`, `thread_id`, `server_id`, `command_type`, `argument`
# TableParser:409 27373 Storage engine: CSV
# SchemaIterator:3289 27373 Next schema object: mysql general_log
# TableParser:409 27373 Storage engine: CSV
# TableParser:409 27373 Storage engine: CSV
Can't use an undefined value as a HASH reference at /usr/bin/pt-duplicate-key-checker line 3658.