/usr/lib/ is in qtdeclarative5-unity-notifications-plugin 0.1.3+15.10.20151021-0ubuntu1.
This file is owned by root:root, with mode 0o755.
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/usr/lib/x86_64-linux-gnu/
/usr/lib/x86_64-linux-gnu/unity8/
/usr/lib/x86_64-linux-gnu/unity8/qml/
/usr/lib/x86_64-linux-gnu/unity8/qml/Unity/
/usr/lib/x86_64-linux-gnu/unity8/qml/Unity/Notifications/
/usr/lib/x86_64-linux-gnu/unity8/qml/Unity/Notifications/libnotifyplugin.so.1.0.0
/usr/lib/x86_64-linux-gnu/unity8/qml/Unity/Notifications/libnotifyclientplugin.so.1.0.0
/usr/lib/x86_64-linux-gnu/unity8/qml/Unity/Notifications/qmldir
/usr/lib/x86_64-linux-gnu/unity8/qml/Unity/Notifications/libnotifyclientplugin.so.1
/usr/lib/x86_64-linux-gnu/unity8/qml/Unity/Notifications/libnotifyplugin.so.1
/usr/lib/x86_64-linux-gnu/unity8/qml/Unity/Notifications/libnotifyplugin.so
/usr/lib/x86_64-linux-gnu/unity8/qml/Unity/Notifications/libnotifyclientplugin.so