mcs4010_autopilot_cross_engine_join, mcs7238_regression_MCOL-830 fails randomly

mysqltest: At line 50: query 'select count(*) from nation n, region r where n.n_regionkey = r.r_regionkey and r.r_regionkey = 2' failed: ER_INTERNAL_ERROR (1815): Internal error: CrossEngineStep::execute() Set or verify credentials in CrossEngineSupport section of Columnstore.xml. (2006) (Server has gone away)

The result from queries just before the failure was:

< snip >

  `n_name` char(25) DEFAULT NULL,

  `n_regionkey` int(11) DEFAULT NULL,

  `n_comment` varchar(152) DEFAULT NULL

) ENGINE=Columnstore DEFAULT CHARSET=utf8mb3 COLLATE=utf8mb3_general_ci

LOAD DATA INFILE '/data/qa/source/dbt3/1m/nation.tbl' INTO TABLE nation FIELDS TERMINATED BY '|';

create table region (

r_regionkey int,

r_name char (25),

r_comment varchar (152)

) engine=innodb;

SHOW CREATE TABLE region;

Table	Create Table

region	CREATE TABLE `region` (

  `r_regionkey` int(11) DEFAULT NULL,

  `r_name` char(25) DEFAULT NULL,

  `r_comment` varchar(152) DEFAULT NULL

) ENGINE=InnoDB DEFAULT CHARSET=utf8mb3 COLLATE=utf8mb3_general_ci

insert into region values (1, 'AMERICA', 'hs use ironic, even requests. s');

insert into region values (2, 'ASIA', 'ges. thinly even pinto beans ca');

select count(*) from nation n, region r where n.n_regionkey = r.r_regionkey and r.r_regionkey = 2;

More results from queries before failure can be found in /var/tmp/mtr/log/mcs4010_autopilot_cross_engine_join.log

Warnings from just before the error:

Error 1815 Internal error: CrossEngineStep::execute() Set or verify credentials in CrossEngineSupport section of Columnstore.xml. (2006) (Server has gone away)