/usr/ is in libarcus-dev 3.1.0-1ubuntu1.
This file is owned by root:root, with mode 0o755.
..
/usr/lib/x86_64-linux-gnu/cmake/
/usr/lib/x86_64-linux-gnu/cmake/Arcus/
/usr/lib/
/usr/lib/x86_64-linux-gnu/
/usr/include/
/usr/include/Arcus/
/usr/include/Arcus/ArcusExport.h
/usr/include/Arcus/Error.h
/usr/include/Arcus/MessageTypeStore.h
/usr/include/Arcus/Socket.h
/usr/include/Arcus/SocketListener.h
/usr/include/Arcus/Types.h
/usr/lib/x86_64-linux-gnu/cmake/Arcus/Arcus-targets-none.cmake
/usr/lib/x86_64-linux-gnu/cmake/Arcus/Arcus-targets.cmake
/usr/lib/x86_64-linux-gnu/cmake/Arcus/ArcusConfig.cmake
/usr/lib/x86_64-linux-gnu/cmake/Arcus/ArcusConfigVersion.cmake
/usr/share/
/usr/share/doc/
/usr/share/doc/libarcus-dev/
/usr/share/doc/libarcus-dev/copyright
/usr/lib/x86_64-linux-gnu/libArcus.so
/usr/share/doc/libarcus-dev/changelog.Debian.gz