/usr/ is in cl-flexichain 1.5.1.dfsg.1-3.
This file is owned by root:root, with mode 0o755.
..
/usr/share/
/usr/share/doc/
/usr/share/doc/cl-flexichain/
/usr/share/doc/cl-flexichain/changelog.Debian.gz
/usr/share/doc/cl-flexichain/copyright
/usr/share/common-lisp/
/usr/share/common-lisp/source/
/usr/share/common-lisp/source/flexichain/
/usr/share/common-lisp/source/flexichain/flexichain.asd
/usr/share/common-lisp/source/flexichain/flexicursor.lisp
/usr/share/common-lisp/source/flexichain/flexirank.lisp
/usr/share/common-lisp/source/flexichain/version.lisp-expr
/usr/share/common-lisp/source/flexichain/utilities.lisp
/usr/share/common-lisp/source/flexichain/flexichain-package.lisp
/usr/share/common-lisp/source/flexichain/flexichain.lisp
/usr/share/common-lisp/systems/
/usr/share/common-lisp/systems/flexichain.asd