/usr/ is in libuser1-dev 1:0.56.9.dfsg.1-1.2ubuntu2.
This file is owned by root:root, with mode 0o755.
..
/usr/share/
/usr/share/doc/
/usr/share/doc/libuser1-dev/
/usr/share/doc/libuser1-dev/examples/
/usr/share/doc/libuser1-dev/examples/lookup.c
/usr/share/doc/libuser1-dev/examples/enum.c
/usr/share/doc/libuser1-dev/examples/field.c
/usr/share/doc/libuser1-dev/examples/testuser.c
/usr/share/doc/libuser1-dev/examples/homedir.c
/usr/share/doc/libuser1-dev/examples/prompt.c
/usr/share/doc/libuser1-dev/copyright
/usr/include/
/usr/include/libuser/
/usr/include/libuser/user.h
/usr/include/libuser/error.h
/usr/include/libuser/config.h
/usr/include/libuser/entity.h
/usr/include/libuser/user_private.h
/usr/include/libuser/prompt.h
/usr/lib/
/usr/lib/pkgconfig/
/usr/lib/pkgconfig/libuser.pc
/usr/lib/libuser.la
/usr/lib/libuser/
/usr/lib/libuser/libuser_files.la
/usr/lib/libuser/libuser_shadow.la
/usr/share/doc/libuser1-dev/changelog.Debian.gz
/usr/lib/libuser.so