main.userstat failed in buildbot with CryptGenRandom error or Unknown SSL error

main.userstat 'innodb_plugin'            w2 [ fail ]

        Test ended at 2017-05-20 06:44:00

CURRENT_TEST: main.userstat

mysqltest: At line 37: query 'connect  ssl_con,localhost,root,,,,,SSL' failed: 2026: SSL connection error: CryptGenRandom error

The result from queries just before the failure was:

< snip >

show columns from information_schema.table_statistics;

Field	Type	Null	Key	Default	Extra

TABLE_SCHEMA	varchar(192)	NO			

TABLE_NAME	varchar(192)	NO			

ROWS_READ	bigint(21)	NO		0	

ROWS_CHANGED	bigint(21)	NO		0	

ROWS_CHANGED_X_INDEXES	bigint(21)	NO		0	

set @save_general_log=@@global.general_log;

set @@global.general_log=0;

set @@global.userstat=1;

flush status;

create table t1 (a int, primary key (a), b int default 0) engine=innodb;

insert into t1 (a) values (1),(2),(3),(4);

update t1 set b=1;

update t1 set b=5 where a=2;

delete from t1 where a=3;

/* Empty query */

select * from t1 where a=999;

a	b

drop table t1;