Ubuntu 24.04 x64: Sometimes hundreds of tests failing

Sometimes Ubuntu 24.04 x64 targets:

• ubuntu-24.04-x64-x11-tests
• ubuntu-24.04-x64-developer-build-x11-tests

have failed with 200, 500 or even 600 failing tests with QDEBUG prints flooding in 60,000 - 80,000 lines.

Not sure are those prints causing more failings, or just a symptom of something else. They are of course visible because test has failed, but with this amount of tests failing, it might be worth to investigate could this flooding of qdebug prints be connected to the rootcause, and possibly suppress qdebug prints temporarily to test could it decrease the amount of failings with Ubuntu 24.04 x64 or not.

Prints are from deleteLater -functionality:

• https://bugreports.qt.io/browse/QTBUG-120124
• https://codereview.qt-project.org/c/qt/qtbase/+/525431

Issue visible i.e. here:

• Target: ubuntu-24.04-x64-developer-build-x11-tests 331 fails
• Tests: https://testresults.qt.io/coin/integration/qt/qt5/tasks/nightly1733694301 

• qtbase tests:

• • 1047 QDEBUG prints flooding
  • https://testresults.qt.io/coin/api/log/qt/qtbase/900f427944f0a660debe662b51eda5c957c765f7/LinuxUbuntu_24_04x86_64LinuxUbuntu_24_04x86_64GCCqtci-linux-Ubuntu-24.04-x86_64-51-e3899fInsignificantTests_PinCores_Sccache_TestOnly/53c98aab100e5cbeacefbcafde7266db785bf1ad/forceRun/test_1733695903/log.txt.gz (link fixed)

• CI metrics for those testresults:
  • https://testresults.qt.io/grafana/d/ce11sn92oenswe/ci-metrics-e28093-ci-testresults?orgId=1&var-testresult_id=nightly1733694301&var-platform=ubuntu-24.04-x64-developer-build-x11-tests&from=now-90d&to=now

I.e. lots of "Increased/Decreased" "scope level to" is visible:

build.go:404: [     0.142 D] qt.core.qobject.deletelater unknown:0 unknown()  -  Increased QThread(0x5bec1b7cf140, name = "Qt mainThread") scope level to 1
build.go:404: [     0.142 D] qt.core.qobject.deletelater unknown:0 unknown()  -  Increased QDBusConnectionManager(0x756535d56ce0) scope level to 1
build.go:404: [     0.142 D] qt.core.qobject.deletelater unknown:0 unknown()  -  Decreased QThread(0x5bec1b7cf140, name = "Qt mainThread") scope level to 0
build.go:404: [     0.142 D] qt.core.qobject.deletelater unknown:0 unknown()  -  Decreased QDBusConnectionManager(0x756535d56ce0) scope level to 0
build.go:404: [     0.142 D] qt.core.qobject.deletelater unknown:0 unknown()  -  Increased QDBusConnectionManager(0x756535d56ce0) scope level to 1
build.go:404: [     0.143 D] qt.core.qobject.deletelater unknown:0 unknown()  -  Decreased QDBusConnectionManager(0x756535d56ce0) scope level to 0
build.go:404: [     0.146 D] qt.core.qobject.deletelater unknown:0 unknown()  -  Increased QDBusConnectionManager(0x756535d56ce0) scope level to 1
build.go:404: [     0.146 D] qt.core.qobject.deletelater unknown:0 unknown()  -  Decreased QDBusConnectionManager(0x756535d56ce0) scope level to 0
build.go:404: [     0.146 D] qt.core.qobject.deletelater unknown:0 unknown()  -  Increased QDBusConnectionManager(0x756535d56ce0) scope level to 1
build.go:404: [     0.146 D] qt.core.qobject.deletelater unknown:0 unknown()  -  Decreased QDBusConnectionManager(0x756535d56ce0) scope level to 0 

Found similar amount of failings from Ubuntu 22.04 target:

• Target: ubuntu-22.04-developer-build-x11-tests with 615 failings
• CI metrics: https://testresults.qt.io/grafana/d/ce11sn92oenswe/ci-metrics-e28093-ci-testresults?orgId=1&var-testresult_id=nightly1732657502&var-platform=ubuntu-22.04-developer-build-x11-tests&from=now-30d&to=now
• Testresults: https://testresults.qt.io/coin/integration/qt/qt5/tasks/nightly1732657502

More comparable tests with same failings when target has multiple tests failing:

Testresults:

https://testresults.qt.io/coin/integration/qt/qt5/tasks/web_qt_qt5_1733238741182 1st run for a new round - Liang
https://testresults.qt.io/coin/integration/qt/qt5/tasks/web_qt_qt5_1733298357821 2nd run for a new round - Liang
https://testresults.qt.io/coin/integration/qt/qt5/tasks/web_qt_qt5_1733312693998 3rd run for a new round - Liang

https://testresults.qt.io/coin/integration/qt/qt5/tasks/web_qt_qt5_1733320551345 1st run of new PS – Liang
https://testresults.qt.io/coin/integration/qt/qt5/tasks/web_qt_qt5_1733340592117 2nd run of new PS – Liang
https://testresults.qt.io/coin/integration/qt/qt5/tasks/web_qt_qt5_1733392356629 3rd run of new PS – Liang
https://testresults.qt.io/coin/integration/qt/qt5/tasks/web_qt_qt5_1733477983161 4th run of new PS – Liang

Testresults in CI metrics:

ci-metrics-e28093-ci-testresults?orgId=1&var-testresult_id=web_qt_qt5_1733238741182 1st run for a new round - Liang
ci-metrics-e28093-ci-testresults?orgId=1&var-testresult_id=web_qt_qt5_1733298357821 2nd run for a new round - Liang
ci-metrics-e28093-ci-testresults?orgId=1&var-testresult_id=web_qt_qt5_1733312693998 3rd run for a new round - Liang

ci-metrics-e28093-ci-testresults?orgId=1&var-testresult_id=web_qt_qt5_1733320551345 1st run of new PS – Liang
ci-metrics-e28093-ci-testresults?orgId=1&var-testresult_id=web_qt_qt5_1733340592117 2nd run of new PS – Liang
ci-metrics-e28093-ci-testresults?orgId=1&var-testresult_id=web_qt_qt5_1733392356629 3rd run of new PS – Liang
ci-metrics-e28093-ci-testresults?orgId=1&var-testresult_id=web_qt_qt5_1733477983161 4th run of new PS – Liang