tst_QSocks5SocketEngine::simpleConnectToIMAP() is flaky on Ubuntu

agent:2021/09/08 15:53:02 runner.go:249: Re-running tests/auto/network/socket/qsocks5socketengine with TESTARGS=simpleConnectToIMAP
[...]

agent:2021/09/08 15:53:03 build.go:391: testserver: docker-compose version 1.24.1, build 4667896b
agent:2021/09/08 15:53:03 build.go:391: env TEST_DOMAIN=test-net.qt.local SHARED_DATA=/home/qt/work/qt/tqtc-qtbase/mkspecs/features/unsupported/../data/testserver SHARED_SERVICE=bridge-network \
    docker-compose -f /home/qt/work/qt/tqtc-qtbase/tests/testserver/docker-compose-bridge-network.yml up --build -d --force-recreate --timeout 1 danted apache2 cyrus \
    && make -f Makefile check_network \
    && env TEST_DOMAIN=test-net.qt.local SHARED_DATA=/home/qt/work/qt/tqtc-qtbase/mkspecs/features/unsupported/../data/testserver SHARED_SERVICE=bridge-network \
        docker-compose -f /home/qt/work/qt/tqtc-qtbase/tests/testserver/docker-compose-bridge-network.yml down --timeout 1
agent:2021/09/08 15:53:04 build.go:391: The MACHINE_IP variable is not set. Defaulting to a blank string.
agent:2021/09/08 15:53:04 build.go:391: Building apache2
[...]

Recreating qt-test-server-danted    ... [32mdone[0m
[1Bmake[1]: Entering directory '/home/qt/work/qt/tqtc-qtbase/tests/auto/network/socket/qsocks5socketengine'
agent:2021/09/08 15:53:17 build.go:391: /home/qt/work/qt/tqtc-qtbase/tests/auto/network/socket/qsocks5socketengine/target_wrapper.sh  ./tst_qsocks5socketengine simpleConnectToIMAP -maxwarnings 0
agent:2021/09/08 15:53:17 build.go:391: ********* Start testing of tst_QSocks5SocketEngine *********
agent:2021/09/08 15:53:17 build.go:391: Config: Using QtTest library 5.15.7, Qt 5.15.7 (x86_64-little_endian-lp64 shared (dynamic) debug build; by GCC 9.3.0), ubuntu 18.04
agent:2021/09/08 15:53:18 build.go:391: PASS   : tst_QSocks5SocketEngine::initTestCase()
agent:2021/09/08 15:53:48 build.go:391: FAIL!  : tst_QSocks5SocketEngine::simpleConnectToIMAP() 'socketDevice.waitForRead()' returned FALSE. (Socket error:Network operation timed out)
agent:2021/09/08 15:53:48 build.go:391:    Loc: [tst_qsocks5socketengine.cpp(312)]
agent:2021/09/08 15:53:48 build.go:391: PASS   : tst_QSocks5SocketEngine::cleanupTestCase()
agent:2021/09/08 15:53:48 build.go:391: Totals: 2 passed, 1 failed, 0 skipped, 0 blacklisted, 31306ms
agent:2021/09/08 15:53:48 build.go:391: ********* Finished testing of tst_QSocks5SocketEngine *********

agent:2021/09/07 20:55:32 build.go:391: test 461
agent:2021/09/07 20:55:32 build.go:391:         Start 461: tst_qsocks5socketengine-setup
agent:2021/09/07 20:55:32 build.go:391: 461: Test command: /usr/local/bin/docker-compose "-f" "/home/qt/work/qt/qtbase/tests/testserver/docker-compose-bridge-network.yml" "up" "--build" "-d" "--force-recreate" "--timeout" "1" "danted" "apache2" "cyrus"
agent:2021/09/07 20:55:32 build.go:391: 461: Environment variables: 
agent:2021/09/07 20:55:32 build.go:391: 461:  testserver=docker-compose version 1.24.1, build 4667896b
agent:2021/09/07 20:55:32 build.go:391: 461:  TEST_DOMAIN=test-net.qt.local
agent:2021/09/07 20:55:32 build.go:391: 461:  SHARED_DATA=/home/qt/work/install/mkspecs/features/data/testserver
agent:2021/09/07 20:55:32 build.go:391: 461:  SHARED_SERVICE=bridge-network
agent:2021/09/07 20:55:32 build.go:391: 461: Test timeout computed to be: 1500
agent:2021/09/07 20:55:33 build.go:391: 461: The MACHINE_IP variable is not set. Defaulting to a blank string.
agent:2021/09/07 20:55:33 build.go:391: 461: Creating network "testserver_default" with the default driver
agent:2021/09/07 20:55:33 build.go:391: 461: Building apache2
[...]

Creating qt-test-server-danted    ... done

agent:2021/09/07 20:55:37 build.go:391: 460/621 Test #461: tst_qsocks5socketengine-setup ........................   Passed    5.00 sec
agent:2021/09/07 20:55:37 build.go:391: test 460
agent:2021/09/07 20:55:37 build.go:391:         Start 460: tst_qsocks5socketengine
agent:2021/09/07 20:55:37 build.go:391: 460: Test command: /opt/cmake-3.21.1/bin/cmake "-P" "/home/qt/work/qt/qtbase_standalone_tests/tests/auto/network/socket/qsocks5socketengine/tst_qsocks5socketengineWrapperDebug.cmake"
agent:2021/09/07 20:55:37 build.go:391: 460: Environment variables: 
agent:2021/09/07 20:55:37 build.go:391: 460:  testserver=docker-compose version 1.24.1, build 4667896b
agent:2021/09/07 20:55:37 build.go:391: 460:  TEST_DOMAIN=test-net.qt.local
agent:2021/09/07 20:55:37 build.go:391: 460:  SHARED_DATA=/home/qt/work/install/mkspecs/features/data/testserver
agent:2021/09/07 20:55:37 build.go:391: 460:  SHARED_SERVICE=bridge-network
agent:2021/09/07 20:55:37 build.go:391: 460: Test timeout computed to be: 1500
agent:2021/09/07 20:55:37 build.go:391: 460: ********* Start testing of tst_QSocks5SocketEngine *********
agent:2021/09/07 20:55:37 build.go:391: 460: Config: Using QtTest library 6.2.0, Qt 6.2.0 (x86_64-little_endian-lp64 shared (dynamic) debug build; by GCC 9.3.0), ubuntu 20.04
[...]

agent:2021/09/07 20:56:11 build.go:391: 460: FAIL!  : tst_QSocks5SocketEngine::simpleConnectToIMAP() 'socketDevice.waitForRead()' returned FALSE. (Socket error:Network operation timed out)
agent:2021/09/07 20:56:11 build.go:391: 460:    Loc: [/home/qt/work/qt/qtbase/tests/auto/network/socket/qsocks5socketengine/tst_qsocks5socketengine.cpp(316)]