mtr failure on Ubuntu Utopic, mysqlhotcopy fails with wrong error(255)

tests mysqlhotcopy_archive and mysqlhotcopy_myisam fail on Ubuntu Utopic:

george@ubuntu1410pkg:~/packaging/mysql-5.6.21/mysql-test$ ./mtr mysqlhotcopy_archive
Logging: ./mtr mysqlhotcopy_archive
2014-11-24 10:51:14 31013 [Warning] Buffered warning: Changed limits: max_open_files: 1024 (requested 5000)

2014-11-24 10:51:14 31013 [Warning] Buffered warning: Changed limits: table_cache: 431 (requested 2000)

2014-11-24 10:51:14 31013 [Note] Plugin 'FEDERATED' is disabled.
2014-11-24 10:51:14 31013 [Note] Binlog end
2014-11-24 10:51:14 31013 [Note] Shutting down plugin 'MyISAM'
2014-11-24 10:51:14 31013 [Note] Shutting down plugin 'CSV'
MySQL Version 5.6.21
Checking supported features...
 - SSL connections supported
Collecting tests...
Removing old var directory...
Creating var directory '/home/george/packaging/mysql-5.6.21/mysql-test/var'...
Installing system database...

==============================================================================

TEST RESULT TIME (ms) or COMMENT
--------------------------------------------------------------------------

worker[1] Using MTR_BUILD_THREAD 300, with reserved ports 13000..13009
main.mysqlhotcopy_archive [ fail ]
        Test ended at 2014-11-24 10:51:22

CURRENT_TEST: main.mysqlhotcopy_archive
Warning: /home/george/packaging/mysql-5.6.21/scripts/mysqlhotcopy is deprecated and will be removed in a future version.
Warning: /home/george/packaging/mysql-5.6.21/scripts/mysqlhotcopy is deprecated and will be removed in a future version.
Warning: /home/george/packaging/mysql-5.6.21/scripts/mysqlhotcopy is deprecated and will be removed in a future version.
Warning: /home/george/packaging/mysql-5.6.21/scripts/mysqlhotcopy is deprecated and will be removed in a future version.
Warning: /home/george/packaging/mysql-5.6.21/scripts/mysqlhotcopy is deprecated and will be removed in a future version.
Warning: /home/george/packaging/mysql-5.6.21/scripts/mysqlhotcopy is deprecated and will be removed in a future version.
Can't hotcopy to '/home/george/packaging/mysql-5.6.21/mysql-test/var/mysqld.1/data/hotcopy_save' because directory
already exist and the --allowold or --addtodest options were not given.
mysqltest: In included file "./include/mysqlhotcopy.inc":
included from ./include/mysqlhotcopy.inc at line 112:
At line 111: command "$MYSQLHOTCOPY --quiet -S $MASTER_MYSOCK -u root hotcopy_test hotcopy_save" failed with wrong error: 255

The result from queries just before the failure was:
< snip >
t2.ARZ
t2.frm
t3.ARZ
t3.frm
DROP DATABASE hotcopy_save;
db.opt
t1.ARZ
t1.frm
t2.ARZ
t2.frm
t3.ARZ
t3.frm
DROP DATABASE hotcopy_save;
db.opt
t1.ARZ
t1.frm
t2.ARZ
t2.frm
t3.ARZ
t3.frm

More results from queries before failure can be found in /home/george/packaging/mysql-5.6.21/mysql-test/var/log/mysqlhotcopy_archiv
e.log

 - saving '/home/george/packaging/mysql-5.6.21/mysql-test/var/log/main.mysqlhotcopy_archive/' to '/home/george/packaging/mysql-5.6.
21/mysql-test/var/log/main.mysqlhotcopy_archive/'
--------------------------------------------------------------------------
The servers were restarted 0 times
Spent 0.000 of 10 seconds executing testcases

Completed: Failed 1/1 tests, 0.00% were successful.

Failing test(s): main.mysqlhotcopy_archive

The log files in var/log may give you some hint of what went wrong.

If you want to report this error, please read first the documentation
at http://dev.mysql.com/doc/mysql/en/mysql-test-suite.html

mysql-test-run: *** ERROR: there were failing test cases