/usr/ is in libgail-dev 2.24.30-1ubuntu1.
This file is owned by root:root, with mode 0o755.
..
/usr/lib/x86_64-linux-gnu/
/usr/lib/x86_64-linux-gnu/pkgconfig/
/usr/lib/
/usr/lib/x86_64-linux-gnu/pkgconfig/gail.pc
/usr/lib/x86_64-linux-gnu/libgailutil.a
/usr/include/
/usr/include/gail-1.0/
/usr/include/gail-1.0/gail/
/usr/include/gail-1.0/gail/gailwidget.h
/usr/include/gail-1.0/libgail-util/
/usr/include/gail-1.0/libgail-util/gail-util.h
/usr/include/gail-1.0/libgail-util/gailmisc.h
/usr/include/gail-1.0/libgail-util/gailtextutil.h
/usr/share/
/usr/share/doc/
/usr/share/doc/libgail-dev/
/usr/share/doc/libgail-dev/copyright
/usr/lib/x86_64-linux-gnu/libgailutil.so
/usr/share/doc/libgail-dev/changelog.Debian.gz