/usr/ is in libgisi-dev 0.1.0-2.
This file is owned by root:root, with mode 0o755.
..
/usr/include/
/usr/include/gisi-1.0/
/usr/include/gisi-1.0/call.h
/usr/include/gisi-1.0/clients.h
/usr/include/gisi-1.0/gisi/
/usr/include/gisi-1.0/gisi/client.h
/usr/include/gisi-1.0/gisi/common.h
/usr/include/gisi-1.0/gisi/iter.h
/usr/include/gisi-1.0/gisi/libgisi.h
/usr/include/gisi-1.0/gisi/message.h
/usr/include/gisi-1.0/gisi/modem.h
/usr/include/gisi-1.0/gisi/netlink.h
/usr/include/gisi-1.0/gisi/pep.h
/usr/include/gisi-1.0/gisi/phonet.h
/usr/include/gisi-1.0/gisi/pipe.h
/usr/include/gisi-1.0/gisi/server.h
/usr/include/gisi-1.0/gisi/socket.h
/usr/include/gisi-1.0/gisicomm.h
/usr/include/gisi-1.0/gpds.h
/usr/include/gisi-1.0/gss.h
/usr/include/gisi-1.0/info.h
/usr/include/gisi-1.0/mtc.h
/usr/include/gisi-1.0/network.h
/usr/include/gisi-1.0/sim.h
/usr/include/gisi-1.0/simauth.h
/usr/include/gisi-1.0/sms.h
/usr/include/gisi-1.0/ss.h
/usr/lib/
/usr/lib/x86_64-linux-gnu/
/usr/lib/x86_64-linux-gnu/pkgconfig/
/usr/lib/x86_64-linux-gnu/pkgconfig/libgisi.pc
/usr/share/
/usr/share/doc/
/usr/share/doc/libgisi-dev/
/usr/share/doc/libgisi-dev/copyright
/usr/share/vala/
/usr/share/vala/vapi/
/usr/share/vala/vapi/libgisi.vapi
/usr/lib/x86_64-linux-gnu/libgisi.so
/usr/share/doc/libgisi-dev/changelog.Debian.gz