http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58678
--- Comment #57 from David Kredba <nheghathivhistha at gmail dot com> --- I got it again with trunk revision 209048: /usr/bin/x86_64-pc-linux-gnu-g++ -fPIC -flto=4 -fuse-linker-plugin -O2 -ggdb -pipe -march=core2 -mtune=core2 -mno-3dnow -mno-sse4.2 -mno-avx -mno-xop -mno-fma4 -mno-sse4a -Wnon-virtual-dtor -Wno-long-long -Wundef -Wcast-align -Wchar-subscripts -Wall -W -Wpointer-arith -Wformat-security -fno-exceptions -DQT_NO_EXCEPTIONS -fno-check-new -fno-common -Woverloaded-virtual -fno-threadsafe-statics -fvisibility=hidden -fvisibility-inlines-hidden -Wl,--enable-new-dtags -Wl,--no-undefined -lc -flto=4 -fuse-linker-plugin -Wl,--as-needed -Wl,-O2 -Wl,-flto -O2 -ggdb -pipe -march=core2 -mtune=core2 -mno-3dnow -mno-sse4.2 -mno-avx -mno-xop -mno-fma4 -mno-sse4a -shared -Wl,-soname,phonon.so -o lib/phonon.so CMakeFiles/python_module_PyKDE4_phonon.dir/sip/phonon/sipphononpart0.cpp.o CMakeFiles/python_module_PyKDE4_phonon.dir/sip/phonon/sipphononpart1.cpp.o CMakeFiles/python_module_PyKDE4_phonon.dir/sip/phonon/sipphononpart2.cpp.o CMakeFiles/python_module_PyKDE4_phonon.dir/sip/phonon/sipphononpart3.cpp.o CMakeFiles/python_module_PyKDE4_phonon.dir/sip/phonon/sipphononpart4.cpp.o CMakeFiles/python_module_PyKDE4_phonon.dir/sip/phonon/sipphononpart5.cpp.o CMakeFiles/python_module_PyKDE4_phonon.dir/sip/phonon/sipphononpart6.cpp.o CMakeFiles/python_module_PyKDE4_phonon.dir/sip/phonon/sipphononpart7.cpp.o -lpython3.2 -lphonon /usr/lib64/qt4/libQtDBus.so /usr/lib64/qt4/libQtCore.so -lpthread /usr/lib64/qt4/libQtGui.so -Wl,-rpath,/usr/lib64/qt4: /tmp/ccpIV11w.ltrans24.ltrans.o: In function `__base_dtor ': /usr/include/phonon/backendcapabilities.h:57: undefined reference to `vtable for Phonon::BackendCapabilities::Notifier' /usr/include/phonon/backendcapabilities.h:57: undefined reference to `vtable for Phonon::BackendCapabilities::Notifier' /usr/include/phonon/backendcapabilities.h:57: undefined reference to `vtable for Phonon::BackendCapabilities::Notifier' collect2: error: ld returned 1 exit status And it is sipphononpart5.cpp.o again. I use Markus's binutils patch (now trunk binutils got it too! :-) ) and the only patch more to revision 209048 is the one from Martin Jambor (Simple enhancements to dumping in ipa.c and ipa-cp.c). It fails with python-3.2 only, python 2.7 and 3.3 version looks to be fine. Without LTO it compiles fine. Both binutils' nm and gcc-nm returns: no symbols for /usr/lib64/libphonon.so.4.7.1. But mc (Internal viewer of a Midnight Commander) can se them: 00000000000273f0 T Phonon::BackendCapabilities::notifier() List of vtables inside /usr/lib64/libphonon.so.4.7.1: U vtable for __cxxabiv1::__class_type_info U vtable for __cxxabiv1::__si_class_type_info U vtable for __cxxabiv1::__vmi_class_type_info 000000000026d580 V vtable for Phonon::SeekSlider 000000000026dd80 V vtable for Phonon::AudioOutput 000000000026dc00 V vtable for Phonon::MediaObject 000000000026e0c0 V vtable for Phonon::PulseStream 000000000026cb40 V vtable for Phonon::VideoPlayer 000000000026ce00 V vtable for Phonon::VideoWidget 000000000026c380 V vtable for Phonon::EffectWidget 000000000026c1c0 V vtable for Phonon::GlobalConfig 000000000026e180 V vtable for Phonon::PulseSupport 000000000026d340 V vtable for Phonon::VolumeSlider 000000000026e000 V vtable for Phonon::AudioDataOutput 000000000026c900 V vtable for Phonon::MediaController 000000000026d880 V vtable for Phonon::StreamInterface 000000000026d8c0 V vtable for Phonon::MediaNodePrivate 000000000026db40 V vtable for Phonon::VolumeFaderEffect 000000000026e280 V vtable for Phonon::MediaSourcePrivate 000000000026df00 V vtable for Phonon::AbstractAudioOutput 000000000026e2c0 V vtable for Phonon::AbstractMediaStream 000000000026c780 V vtable for Phonon::AbstractMediaStreamPrivate 000000000026dcc0 V vtable for Phonon::Effect 000000000026dea0 V vtable for Phonon::MediaNode Objdump -t see no symbols, -T see symbols. I rebuild phonon by the same compiler/binutils as pykde4. Could you kindly please check if you are affected too? Thank you in advance.