main.range_vs_index_merge_innodb failed in buildbot, server has gone away

main.range_vs_index_merge_innodb 'xtradb' w4 [ fail ]

        Test ended at 2018-02-10 19:23:45

CURRENT_TEST: main.range_vs_index_merge_innodb

mysqltest: In included file "D:/winx64-debug/build/src/mysql-test/t/range_vs_index_merge.test": 

included from D:/winx64-debug/build/src/mysql-test/t/range_vs_index_merge_innodb.test at line 6:

At line 794: query 'insert into t1(account_id, login, home_state, work_state)

select 1, 'pw', 'ak', 'ak' from t1' failed: 2006: MySQL server has gone away

The result from queries just before the failure was:

< snip >

KEY user_home_city_indx (home_city),

KEY user_work_city_indx (work_city),

KEY user_first_name_indx (first_name),

KEY user_last_name_indx (last_name)

);

insert into t1(account_id, login, home_state, work_state) values

(1, 'pw', 'ia', 'ia'), (1, 'pw', 'ia', 'ia'), (1, 'pw', 'ia', 'ia'),

(1, 'pw', 'ia', 'ia'), (1, 'pw', 'ia', 'ia'), (1, 'pw', 'ia', 'ia');

insert into t1(account_id, login, home_state, work_state)

select 1, 'pw', 'ak', 'ak' from t1;

insert into t1(account_id, login, home_state, work_state)

select 1, 'pw', 'ak', 'ak' from t1;

insert into t1(account_id, login, home_state, work_state)

select 1, 'pw', 'ak', 'ak' from t1;

insert into t1(account_id, login, home_state, work_state)

select 1, 'pw', 'ak', 'ak' from t1;

insert into t1(account_id, login, home_state, work_state)

select 1, 'pw', 'ak', 'ak' from t1;

insert into t1(account_id, login, home_state, work_state)

select 1, 'pw', 'ak', 'ak' from t1;