"Unused private field" build failure(s) — clang 3.3

clang -Wall -Werror will fail because bar is private (by default) and never used. g++ does not complain here.
class foo
{
    int bar;
};
PackageVersionSupposed error messageFull log Bug report
clementine 1.1.1+dfsg-2playlistundocommands.h:113:9: error: private field 'column_' is not used [-Werror,-Wunused-private-field] Log
liborcus 0.3.0-8../../include/orcus/odf/ods_handler.hpp:63:41: error: private field 'mp_factory' is not used [-Werror,-Wunused-private-field] Log
libwpg 0.2.1-1./WPGHeader.h:54:16: error: private field 'm_entryCount' is not used [-Werror,-Wunused-private-field] Log
qpid-cpp 0.16-7qpid/client/RdmaConnector.cpp:72:33: error: private field 'initialiser' is not used [-Werror,-Wunused-private-field] Log

4 errors