qwaylandwindow_p.h:199:10: error: ‘bool QtWaylandClient::QWaylandWindow::startSystemMove(const QPoint&)’ marked ‘override’, but does not override

agent:2020/01/28 23:38:16 build.go:220: In file included from qwaylandshmbackingstore.cpp:40:
agent:2020/01/28 23:38:16 build.go:220: qwaylandwindow_p.h:199:10: error: ‘bool QtWaylandClient::QWaylandWindow::startSystemMove(const QPoint&)’ marked ‘override’, but does not override
agent:2020/01/28 23:38:16 build.go:220: bool startSystemMove(const QPoint &pos) override;
agent:2020/01/28 23:38:16 build.go:220: ^~~~~~~~~~~~~~~
agent:2020/01/28 23:38:16 build.go:220: Makefile:3490: recipe for target '.obj/qwaylandshmbackingstore.o' failed
agent:2020/01/28 23:38:16 build.go:220: make[2]: *** [.obj/qwaylandshmbackingstore.o] Error 1
agent:2020/01/28 23:38:16 build.go:220: make[2]: Leaving directory '/home/qt/work/qt/qtwayland/src/client'
agent:2020/01/28 23:38:16 build.go:220: Makefile:75: recipe for target 'sub-client-make_first' failed
agent:2020/01/28 23:38:16 build.go:220: make[1]: *** [sub-client-make_first] Error 2

Build log: https://testresults.qt.io/logs/qt/qtwayland/63a7d95a056500c9fb8be2e1cc38b4bc578e484e/LinuxUbuntu_18_04x86_64LinuxUbuntu_18_04x86_64GCCqtci-linux-Ubuntu-18.04-x86_64-ca0cfe/7dcc2bd59e6528ed5d67b7785142e2f62d5934c7/build_1580253014/log.txt.gz

Details: https://testresults.qt.io/coin/integration/qt/qt5/tasks/1580251880
Tested changes (refs/builds/qtci/5.15/1580251879):
https://codereview.qt-project.org/c/qt/qt5/+/288302 Update submodules on '5.15' in qt/qt5