/usr/ is in libdevhelp-dev 3.22.0-1+b1.
This file is owned by root:root, with mode 0o755.
..
/usr/include/
/usr/include/devhelp-3.0/
/usr/include/devhelp-3.0/devhelp/
/usr/include/devhelp-3.0/devhelp/devhelp.h
/usr/include/devhelp-3.0/devhelp/dh-app.h
/usr/include/devhelp-3.0/devhelp/dh-assistant-view.h
/usr/include/devhelp-3.0/devhelp/dh-assistant.h
/usr/include/devhelp-3.0/devhelp/dh-book-manager.h
/usr/include/devhelp-3.0/devhelp/dh-book-tree.h
/usr/include/devhelp-3.0/devhelp/dh-book.h
/usr/include/devhelp-3.0/devhelp/dh-error.h
/usr/include/devhelp-3.0/devhelp/dh-keyword-model.h
/usr/include/devhelp-3.0/devhelp/dh-language.h
/usr/include/devhelp-3.0/devhelp/dh-link.h
/usr/include/devhelp-3.0/devhelp/dh-sidebar.h
/usr/include/devhelp-3.0/devhelp/dh-window.h
/usr/lib/
/usr/lib/x86_64-linux-gnu/
/usr/lib/x86_64-linux-gnu/pkgconfig/
/usr/lib/x86_64-linux-gnu/pkgconfig/libdevhelp-3.0.pc
/usr/share/
/usr/share/doc/
/usr/share/doc/libdevhelp-dev/
/usr/share/doc/libdevhelp-dev/changelog.Debian.amd64.gz
/usr/share/doc/libdevhelp-dev/changelog.Debian.gz
/usr/share/doc/libdevhelp-dev/copyright
/usr/lib/x86_64-linux-gnu/libdevhelp-3.so