Warnings appear related to anchors used at a QML level.
These warnings aren't shown on Bionic, it is related to change in QT version you get when installing it on different ubuntu versions, btw, QT is brought by ign-gui:
qt on Bionic: 5.9.5
qt on Focal: 5.12
Fixing this should be trivial.
The warnings:
GUI] [Wrn] [Application.cc:669] [QT] file::/MaliputViewerPlugin/FileSelectionArea.qml:41:3: QML QQuickText: Detected anchors on an item that is managed by a layout. This is undefined behavior; use Layout.alignment instead.
[GUI] [Wrn] [Application.cc:669] [QT] file::/MaliputViewerPlugin/FileSelectionArea.qml:41:3: QML QQuickText: Detected anchors on an item that is managed by a layout. This is undefined behavior; use Layout.alignment instead.
[GUI] [Wrn] [Application.cc:669] [QT] file::/MaliputViewerPlugin/FileSelectionArea.qml:41:3: QML QQuickText: Detected anchors on an item that is managed by a layout. This is undefined behavior; use Layout.alignment instead.
[GUI] [Wrn] [Application.cc:669] [QT] file::/MaliputViewerPlugin/FileSelectionArea.qml:41:3: QML QQuickText: Detected anchors on an item that is managed by a layout. This is undefined behavior; use Layout.alignment instead.
[GUI] [Wrn] [Application.cc:669] [QT] file::/MaliputViewerPlugin/FileSelectionArea.qml:41:3: QML QQuickText: Detected anchors on an item that is managed by a layout. This is undefined behavior; use Layout.alignment instead.
[GUI] [Wrn] [Application.cc:669] [QT] file::/MaliputViewerPlugin/FileSelectionArea.qml:41:3: QML QQuickText: Detected anchors on an item that is managed by a layout. This is undefined behavior; use Layout.alignment instead.
[GUI] [Wrn] [Application.cc:669] [QT] file::/MaliputViewerPlugin/FileSelectionArea.qml:41:3: QML QQuickText: Detected anchors on an item that is managed by a layout. This is undefined behavior; use Layout.alignment instead.
[GUI] [Wrn] [Application.cc:669] [QT] file::/MaliputViewerPlugin/FileSelectionArea.qml:41:3: QML QQuickText: Detected anchors on an item that is managed by a layout. This is undefined behavior; use Layout.alignment instead.
[GUI] [Wrn] [Application.cc:669] [QT] file::/MaliputViewerPlugin/FileSelectionArea.qml:41:3: QML QQuickText: Detected anchors on an item that is managed by a layout. This is undefined behavior; use Layout.alignment instead.
[GUI] [Wrn] [Application.cc:669] [QT] file::/MaliputViewerPlugin/FileSelectionArea.qml:41:3: QML QQuickText: Detected anchors on an item that is managed by a layout. This is undefined behavior; use Layout.alignment instead.
[GUI] [Wrn] [Application.cc:669] [QT] file::/MaliputViewerPlugin/LayersSelectionArea.qml:24:3: QML QQuickText: Detected anchors on an item that is managed by a layout. This is undefined behavior; use Layout.alignment instead.
[GUI] [Wrn] [Application.cc:669] [QT] file::/MaliputViewerPlugin/LayersSelectionArea.qml:24:3: QML QQuickText: Detected anchors on an item that is managed by a layout. This is undefined behavior; use Layout.alignment instead.
[GUI] [Wrn] [Application.cc:669] [QT] file::/MaliputViewerPlugin/LayersSelectionArea.qml:24:3: QML QQuickText: Detected anchors on an item that is managed by a layout. This is undefined behavior; use Layout.alignment instead.
[GUI] [Wrn] [Application.cc:669] [QT] file::/MaliputViewerPlugin/LayersSelectionArea.qml:24:3: QML QQuickText: Detected anchors on an item that is managed by a layout. This is undefined behavior; use Layout.alignment instead.
[GUI] [Wrn] [Application.cc:669] [QT] file::/MaliputViewerPlugin/LayersSelectionArea.qml:24:3: QML QQuickText: Detected anchors on an item that is managed by a layout. This is undefined behavior; use Layout.alignment instead.
[GUI] [Wrn] [Application.cc:669] [QT] file::/MaliputViewerPlugin/LayersSelectionArea.qml:24:3: QML QQuickText: Detected anchors on an item that is managed by a layout. This is undefined behavior; use Layout.alignment instead.
[GUI] [Wrn] [Application.cc:669] [QT] file::/MaliputViewerPlugin/LayersSelectionArea.qml:24:3: QML QQuickText: Detected anchors on an item that is managed by a layout. This is undefined behavior; use Layout.alignment instead.
[GUI] [Wrn] [Application.cc:669] [QT] file::/MaliputViewerPlugin/LayersSelectionArea.qml:24:3: QML QQuickText: Detected anchors on an item that is managed by a layout. This is undefined behavior; use Layout.alignment instead.
[GUI] [Wrn] [Application.cc:669] [QT] file::/MaliputViewerPlugin/LayersSelectionArea.qml:24:3: QML QQuickText: Detected anchors on an item that is managed by a layout. This is undefined behavior; use Layout.alignment instead.
[GUI] [Wrn] [Application.cc:669] [QT] file::/MaliputViewerPlugin/LabelsSelectionArea.qml:24:3: QML QQuickText: Detected anchors on an item that is managed by a layout. This is undefined behavior; use Layout.alignment instead.
[GUI] [Wrn] [Application.cc:669] [QT] file::/MaliputViewerPlugin/LabelsSelectionArea.qml:24:3: QML QQuickText: Detected anchors on an item that is managed by a layout. This is undefined behavior; use Layout.alignment instead.
[GUI] [Wrn] [Application.cc:669] [QT] file::/MaliputViewerPlugin/LabelsSelectionArea.qml:24:3: QML QQuickText: Detected anchors on an item that is managed by a layout. This is undefined behavior; use Layout.alignment instead.
[GUI] [Wrn] [Application.cc:669] [QT] file::/MaliputViewerPlugin/InfoArea.qml:19:3: QML QQuickText: Detected anchors on an item that is managed by a layout. This is undefined behavior; use Layout.alignment instead.
[GUI] [Wrn] [Application.cc:669] [QT] file::/MaliputViewerPlugin/InfoArea.qml:30:3: QML TextArea: Detected anchors on an item that is managed by a layout. This is undefined behavior; use Layout.alignment instead.
[GUI] [Wrn] [Application.cc:669] [QT] file::/MaliputViewerPlugin/InfoArea.qml:19:3: QML QQuickText: Detected anchors on an item that is managed by a layout. This is undefined behavior; use Layout.alignment instead.
[GUI] [Wrn] [Application.cc:669] [QT] file::/MaliputViewerPlugin/InfoArea.qml:30:3: QML TextArea: Detected anchors on an item that is managed by a layout. This is undefined behavior; use Layout.alignment instead.
[GUI] [Wrn] [Application.cc:669] [QT] file::/MaliputViewerPlugin/PhaseSelectionArea.qml:20:3: QML QQuickText: Detected anchors on an item that is managed by a layout. This is undefined behavior; use Layout.alignment instead.
[GUI] [Wrn] [Application.cc:669] [QT] file::/MaliputViewerPlugin/PhaseSelectionArea.qml:30:3: QML TreeView: Detected anchors on an item that is managed by a layout. This is undefined behavior; use Layout.alignment instead.
[GUI] [Wrn] [Application.cc:669] [QT] file::/MaliputViewerPlugin/PhaseSelectionArea.qml:20:3: QML QQuickText: Detected anchors on an item that is managed by a layout. This is undefined behavior; use Layout.alignment instead.
[GUI] [Wrn] [Application.cc:669] [QT] file::/MaliputViewerPlugin/PhaseSelectionArea.qml:30:3: QML TreeView: Detected anchors on an item that is managed by a layout. This is undefined behavior; use Layout.alignment instead.
[GUI] [Wrn] [Application.cc:669] [QT] file::/MaliputViewerPlugin/LanesListArea.qml:24:3: QML QQuickText: Detected anchors on an item that is managed by a layout. This is undefined behavior; use Layout.alignment instead.
[GUI] [Wrn] [Application.cc:669] [QT] file::/MaliputViewerPlugin/LanesListArea.qml:35:3: QML TableView: Detected anchors on an item that is managed by a layout. This is undefined behavior; use Layout.alignment instead.
[GUI] [Wrn] [Application.cc:669] [QT] file::/MaliputViewerPlugin/LanesListArea.qml:24:3: QML QQuickText: Detected anchors on an item that is managed by a layout. This is undefined behavior; use Layout.alignment instead.
[GUI] [Wrn] [Application.cc:669] [QT] file::/MaliputViewerPlugin/LanesListArea.qml:35:3: QML TableView: Detected anchors on an item that is managed by a layout. This is undefined behavior; use Layout.alignment instead.
[GUI] [Wrn] [Application.cc:669] [QT] file::/MaliputViewerPlugin/RulesListArea.qml:20:3: QML QQuickText: Detected anchors on an item that is managed by a layout. This is undefined behavior; use Layout.alignment instead.
[GUI] [Wrn] [Application.cc:669] [QT] file::/MaliputViewerPlugin/RulesListArea.qml:30:3: QML TextArea: Detected anchors on an item that is managed by a layout. This is undefined behavior; use Layout.alignment instead.
[GUI] [Wrn] [Application.cc:669] [QT] file::/MaliputViewerPlugin/RulesListArea.qml:20:3: QML QQuickText: Detected anchors on an item that is managed by a layout. This is undefined behavior; use Layout.alignment instead.
[GUI] [Wrn] [Application.cc:669] [QT] file::/MaliputViewerPlugin/RulesListArea.qml:30:3: QML TextArea: Detected anchors on an item that is managed by a layout. This is undefined behavior; use Layout.alignment instead.
Warnings appear related to anchors used at a QML level. These warnings aren't shown on Bionic, it is related to change in QT version you get when installing it on different ubuntu versions, btw, QT is brought by ign-gui:
Fixing this should be trivial.
The warnings: