Building C++ qpidmessaging on RHEL 5 with updated gcc 4.1.2 produces an error:
cc1plus: warnings being treated as errors
/qpidbuilds/trunk/qpid/cpp/src/../include/qpid/RangeSet.h: In instantiation of ‘qpid::RangeSet<qpid::framing::SequenceNumber>’:
/qpidbuilds/trunk/qpid/cpp/src/../include/qpid/framing/SequenceSet.h:32: instantiated from here
/qpidbuilds/trunk/qpid/cpp/src/../include/qpid/RangeSet.h:193: warning: lowering visibility of ‘std::ostream& qpid::operator<<(std::ostream&, const qpid::RangeSet<U>&) [with U = U, T = qpid::framing::SequenceNumber]’ to match its type
make: *** [src/CMakeFiles/qpidmessaging.dir/qpid/messaging/ProtocolRegistry.o] Error 1
The way to silence this warning is to add -Wno-attributes along with -fvisibility=hidden.