/usr/ is in libmrss0-dev 0.19.2-6.
This file is owned by root:root, with mode 0o755.
..
/usr/include/
/usr/include/mrss.h
/usr/lib/
/usr/lib/x86_64-linux-gnu/
/usr/lib/x86_64-linux-gnu/libmrss.a
/usr/lib/x86_64-linux-gnu/pkgconfig/
/usr/lib/x86_64-linux-gnu/pkgconfig/mrss.pc
/usr/share/
/usr/share/doc/
/usr/share/doc/libmrss0-dev/
/usr/share/doc/libmrss0-dev/copyright
/usr/share/doc/libmrss0-dev/examples/
/usr/share/doc/libmrss0-dev/examples/new.c
/usr/share/doc/libmrss0-dev/examples/time.c
/usr/share/doc/libmrss0-dev/examples/parser.c
/usr/share/doc/libmrss0-dev/examples/search.c
/usr/share/doc/libmrss0-dev/examples/write.c
/usr/lib/x86_64-linux-gnu/libmrss.so
/usr/share/doc/libmrss0-dev/changelog.Debian.gz