Compilation error in qtspeech (during qt5.git integration in 'dev')

...
rm -f libqtexttospeech_speechosx_debug.dylib
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/clang++ -stdlib=libc++ -headerpad_max_install_names -fapplication-extension  -arch x86_64 -Wl,-syslibroot,/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.12.sdk -mmacosx-version-min=10.10 -Wl,-rpath,@executable_path/Frameworks -Wl,-rpath,@loader_path/../../lib -single_module -dynamiclib -o libqtexttospeech_speechosx_debug.dylib .obj/debug/qtexttospeech_osx_plugin.o .obj/debug/qtexttospeech_osx.o .obj/debug/moc_qtexttospeech_osx_plugin.o .obj/debug/moc_qtexttospeech_osx.o .obj/debug/moc_qtexttospeech_osx.o  -F/Users/qt/work/qt/qtspeech/lib -F/Users/qt/work/install/lib -framework Cocoa -framework QtTextToSpeech -framework QtCore -framework DiskArbitration -framework IOKit -framework QtGui -framework OpenGL -framework AGL  
duplicate symbol __ZTV22QTextToSpeechEngineOsx in:
    .obj/debug/moc_qtexttospeech_osx.o
duplicate symbol __ZTS22QTextToSpeechEngineOsx in:
    .obj/debug/moc_qtexttospeech_osx.o
duplicate symbol __ZTI22QTextToSpeechEngineOsx in:
    .obj/debug/moc_qtexttospeech_osx.o
duplicate symbol __ZN22QTextToSpeechEngineOsx18qt_static_metacallEP7QObjectN11QMetaObject4CallEiPPv in:
    .obj/debug/moc_qtexttospeech_osx.o
duplicate symbol __ZN22QTextToSpeechEngineOsx11qt_metacallEN11QMetaObject4CallEiPPv in:
    .obj/debug/moc_qtexttospeech_osx.o
duplicate symbol __ZNK22QTextToSpeechEngineOsx10metaObjectEv in:
    .obj/debug/moc_qtexttospeech_osx.o
duplicate symbol __ZN22QTextToSpeechEngineOsx11qt_metacastEPKc in:
    .obj/debug/moc_qtexttospeech_osx.o
duplicate symbol __ZN22QTextToSpeechEngineOsx16staticMetaObjectE in:
    .obj/debug/moc_qtexttospeech_osx.o
ld: 8 duplicate symbols for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)
make[5]: *** [../../../../plugins/texttospeech/libqtexttospeech_speechosx_debug.dylib] Error 1
make[4]: *** [debug-all] Error 2
make[4]: *** Waiting for unfinished jobs....
rm -f libqtexttospeech_speechosx.dylib
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/clang++ -stdlib=libc++ -headerpad_max_install_names -fapplication-extension  -arch x86_64 -Wl,-syslibroot,/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.12.sdk -mmacosx-version-min=10.10 -Wl,-rpath,@executable_path/Frameworks -Wl,-rpath,@loader_path/../../lib -single_module -dynamiclib -o libqtexttospeech_speechosx.dylib .obj/release/qtexttospeech_osx_plugin.o .obj/release/qtexttospeech_osx.o .obj/release/moc_qtexttospeech_osx_plugin.o .obj/release/moc_qtexttospeech_osx.o .obj/release/moc_qtexttospeech_osx.o  -F/Users/qt/work/qt/qtspeech/lib -F/Users/qt/work/install/lib -framework Cocoa -framework QtTextToSpeech -framework QtCore -framework DiskArbitration -framework IOKit -framework QtGui -framework OpenGL -framework AGL  
duplicate symbol __ZTV22QTextToSpeechEngineOsx in:
    .obj/release/moc_qtexttospeech_osx.o
duplicate symbol __ZTS22QTextToSpeechEngineOsx in:
    .obj/release/moc_qtexttospeech_osx.o
duplicate symbol __ZTI22QTextToSpeechEngineOsx in:
    .obj/release/moc_qtexttospeech_osx.o
duplicate symbol __ZN22QTextToSpeechEngineOsx18qt_static_metacallEP7QObjectN11QMetaObject4CallEiPPv in:
    .obj/release/moc_qtexttospeech_osx.o
duplicate symbol __ZN22QTextToSpeechEngineOsx11qt_metacallEN11QMetaObject4CallEiPPv in:
    .obj/release/moc_qtexttospeech_osx.o
duplicate symbol __ZNK22QTextToSpeechEngineOsx10metaObjectEv in:
    .obj/release/moc_qtexttospeech_osx.o
duplicate symbol __ZN22QTextToSpeechEngineOsx11qt_metacastEPKc in:
    .obj/release/moc_qtexttospeech_osx.o
duplicate symbol __ZN22QTextToSpeechEngineOsx16staticMetaObjectE in:
    .obj/release/moc_qtexttospeech_osx.o
ld: 8 duplicate symbols for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)
make[5]: *** [../../../../plugins/texttospeech/libqtexttospeech_speechosx.dylib] Error 1
make[4]: *** [release-all] Error 2
make[3]: *** [sub-osx-make_first] Error 2
make[2]: *** [sub-tts-make_first] Error 2
make[1]: *** [sub-plugins-make_first] Error 2
make: *** [sub-src-make_first] Error 2