/usr/ is in libstdc++6-4.8-dbg 4.8.5-4ubuntu8.
This file is owned by root:root, with mode 0o755.
..
/usr/lib/
/usr/lib/x86_64-linux-gnu/
/usr/lib/x86_64-linux-gnu/debug/
/usr/lib/x86_64-linux-gnu/debug/libstdc++.a
/usr/lib/x86_64-linux-gnu/debug/libstdc++.so.6.0.19
/usr/share/
/usr/share/doc/
/usr/share/gdb/
/usr/share/gdb/auto-load/
/usr/share/gdb/auto-load/usr/
/usr/share/gdb/auto-load/usr/lib/
/usr/share/gdb/auto-load/usr/lib/x86_64-linux-gnu/
/usr/share/gdb/auto-load/usr/lib/x86_64-linux-gnu/debug/
/usr/share/gdb/auto-load/usr/lib/x86_64-linux-gnu/debug/libstdc++.so.6.0.19-gdb.py
/usr/lib/x86_64-linux-gnu/debug/libstdc++.so
/usr/lib/x86_64-linux-gnu/debug/libstdc++.so.6
/usr/share/doc/libstdc++6-4.8-dbg