/usr/share/acl2-8.0dfsg/books/hacking/ is in acl2-books-source 8.0dfsg-1.
This file is owned by root:root, with mode 0o755.
..
/usr/share/acl2-8.0dfsg/books/hacking/all.acl2
/usr/share/acl2-8.0dfsg/books/hacking/all.lisp
/usr/share/acl2-8.0dfsg/books/hacking/bridge.acl2
/usr/share/acl2-8.0dfsg/books/hacking/bridge.lisp
/usr/share/acl2-8.0dfsg/books/hacking/defcode.acl2
/usr/share/acl2-8.0dfsg/books/hacking/defcode.lisp
/usr/share/acl2-8.0dfsg/books/hacking/defstruct-parsing.acl2
/usr/share/acl2-8.0dfsg/books/hacking/defstruct-parsing.lisp
/usr/share/acl2-8.0dfsg/books/hacking/doc-section.lisp
/usr/share/acl2-8.0dfsg/books/hacking/dynamic-make-event-test.acl2
/usr/share/acl2-8.0dfsg/books/hacking/dynamic-make-event-test.lisp
/usr/share/acl2-8.0dfsg/books/hacking/dynamic-make-event.acl2
/usr/share/acl2-8.0dfsg/books/hacking/dynamic-make-event.lisp
/usr/share/acl2-8.0dfsg/books/hacking/evalable-ld-printing.acl2
/usr/share/acl2-8.0dfsg/books/hacking/evalable-ld-printing.lisp
/usr/share/acl2-8.0dfsg/books/hacking/hacker.acl2
/usr/share/acl2-8.0dfsg/books/hacking/hacker.lisp
/usr/share/acl2-8.0dfsg/books/hacking/hacking-xdoc.lisp
/usr/share/acl2-8.0dfsg/books/hacking/progn-bang-enh.acl2
/usr/share/acl2-8.0dfsg/books/hacking/progn-bang-enh.lisp
/usr/share/acl2-8.0dfsg/books/hacking/raw.acl2
/usr/share/acl2-8.0dfsg/books/hacking/raw.lisp
/usr/share/acl2-8.0dfsg/books/hacking/redefun.acl2
/usr/share/acl2-8.0dfsg/books/hacking/redefun.lisp
/usr/share/acl2-8.0dfsg/books/hacking/rewrite-code.acl2
/usr/share/acl2-8.0dfsg/books/hacking/rewrite-code.lisp
/usr/share/acl2-8.0dfsg/books/hacking/subsumption.acl2
/usr/share/acl2-8.0dfsg/books/hacking/subsumption.lisp
/usr/share/acl2-8.0dfsg/books/hacking/table-guard.acl2
/usr/share/acl2-8.0dfsg/books/hacking/table-guard.lisp