vtexplain throwing spurious "got strange results from 'show status'" warnings

[aquarapid]

On recent master (bb4d877):

Since PR #7520 we are seeing warnings when running vtexplain.

Example:

vschema.json:

{
        "ks1": {
                "tables": {
                        "t1": {}
                }
        }
}

schema.sql:

create table t1(c1 int, primary key(c1));

vtexplain run:

vtexplain -schema-file schema.sql -vschema-file vschema.json -shards 1 -sql 'select * from t1;'
W0226 18:39:58.338810  140548 engine.go:410] got strange results from 'show status': []
----------------------------------------------------------------------
select * from t1

1 ks1/-: select * from t1 limit 10001

----------------------------------------------------------------------

Note the warning; it will repeat, once for every shard (if the vschema is a sharded keyspace).