/usr/lib/x86_64-linux-gnu/ is in libphonon4qt5-dev 4:4.8.3-0ubuntu3.
This file is owned by root:root, with mode 0o755.
..
/usr/lib/x86_64-linux-gnu/pkgconfig/
/usr/lib/x86_64-linux-gnu/qt5/
/usr/lib/x86_64-linux-gnu/qt5/mkspecs/
/usr/lib/x86_64-linux-gnu/qt5/mkspecs/modules/
/usr/lib/x86_64-linux-gnu/qt5/mkspecs/modules/qt_phonon4qt5.pri
/usr/lib/x86_64-linux-gnu/qt5/plugins/
/usr/lib/x86_64-linux-gnu/qt5/plugins/designer/
/usr/lib/x86_64-linux-gnu/qt5/plugins/designer/phononwidgets.so
/usr/lib/x86_64-linux-gnu/cmake/
/usr/lib/x86_64-linux-gnu/cmake/phonon4qt5/
/usr/lib/x86_64-linux-gnu/cmake/phonon4qt5/Phonon4Qt5ConfigVersion.cmake
/usr/lib/x86_64-linux-gnu/cmake/phonon4qt5/PhononTargets.cmake
/usr/lib/x86_64-linux-gnu/cmake/phonon4qt5/PhononTargets-debian.cmake
/usr/lib/x86_64-linux-gnu/cmake/phonon4qt5/Phonon4Qt5Config.cmake
/usr/lib/x86_64-linux-gnu/pkgconfig/phonon4qt5.pc
/usr/lib/x86_64-linux-gnu/libphonon4qt5.so