Documentation build failed due to duplicate executable name: "pingpong"

agent:2021/04/21 06:49:16 build.go:379: Call Stack (most recent call first):
agent:2021/04/21 06:49:16 build.go:379:   qtscxml/src/scxmlqml/CMakeLists.txt:1 (qt_internal_add_module)
agent:2021/04/21 06:49:16 build.go:379: -- Tool 'Qt6::qscxmlc' will be built from source.
agent:2021/04/21 06:49:18 build.go:379: CMake Error at qtbase/lib/cmake/Qt6Core/Qt6CoreMacros.cmake:508 (add_executable):
agent:2021/04/21 06:49:18 build.go:379:   add_executable cannot create target "pingpong" because another target with
agent:2021/04/21 06:49:18 build.go:379:   the same name already exists.  The existing target is an executable created
agent:2021/04/21 06:49:18 build.go:379:   in source directory
agent:2021/04/21 06:49:18 build.go:379:   "/home/qt/work/qt/qt5/qtconnectivity/examples/bluetooth/pingpong".  See
agent:2021/04/21 06:49:18 build.go:379:   documentation for policy CMP0002 for more details.
agent:2021/04/21 06:49:18 build.go:379: Call Stack (most recent call first):
agent:2021/04/21 06:49:18 build.go:379:   qtbase/lib/cmake/Qt6Core/Qt6CoreMacros.cmake:475 (_qt_internal_create_executable)
agent:2021/04/21 06:49:18 build.go:379:   qtbase/lib/cmake/Qt6Core/Qt6CoreMacros.cmake:707 (qt6_add_executable)
agent:2021/04/21 06:49:18 build.go:379:   qtscxml/examples/statemachine/statemachine/pingpong/CMakeLists.txt:21 (qt_add_executable)