test-run fails to kill cluster servers in case of an error

[opomuc]

Say we have a Lua test like this:

#!/usr/bin/env tarantool
env = require('test_run')
test_run = env.new()

servers = {'stub1', 'stub2'}
test_run:create_cluster(servers)

local index_table = {}
local error = index_table.nil_value.error -- index nil field

test_run:drop_cluster(servers)
os.exit(0)

When the test crushes, test-run does not kill started in create_cluster servers

[Totktonada]

Confirmed on the current test-run master (0ea84be) using graphql repo:

diff --git a/test/testdata/common_testdata.lua b/test/testdata/common_testdata.lua
index bb1a878..accfed0 100644
--- a/test/testdata/common_testdata.lua
+++ b/test/testdata/common_testdata.lua
@@ -361,6 +361,8 @@ function common_testdata.run_queries(gql_wrapper)
     local test = tap.test('common')
     test:plan(24)
 
+    error('XXX')
+
     local query_1 = [[
         query user_by_order($order_id: String) {
             order_collection(order_id: $order_id) {

$ TEST_RUN_TESTS=common/common make test

[Totktonada]

I'll consider this issue as statement of the problem with 'core = app' tests.